Please excuse my ignorance on the subject as I am just getting into 1911's.

I recently purchased a brand new Springfield 1911 Mil-Spec with full intentions of sending it to the SACS and having work done.  

What are some MUST haves?  This gun will not be carried daily and will be used to shoot every now and then.  No competition or anything of the sort.  

I was thinking about doing their Defense Package, Beavertail Grip Safety, Skeletonized Hammer, and not sure what else?  I don't want to spend another $1500 or anything. LOL

A few things I was wondering… Is it worth it to have them fit the slide to the frame on just a fun shooting pistol that wont be used for anything more than that?  Should anything be done with the safety?  Anything with the guide rod?

Basically point me in the right direction of a few options from the SACS that I want to have done.  

Once again, excuse my ignorance on the topic and thanks for the help!

Edit - Also, are the parts from the SACS the way to go (i.e. - beavertail grip safety, hammer, trigger, etc) or should I supply them with something else to use??

I'd suggest a trigger job to get you a 3.5 to 4 lb clean pull.  You may have a local 1911 smith who can do that for you and save the shipping costs.  You may have to replace the mim fire control parts to get you there.  For sure, get enough rounds through it to know if you have any warranty issues.

All practical advice here. ^

I would personally go with a trigger job as well. My 1911 was worked over by SACS, they include the tool steel parts with the job.

I would also get at least a dovetail front sight put in. The rear on the milspec can be drifted out and replaced with something with tritium if you prefer, not a big deal unless you really want Novak or Bo-mar sights. The front, at least, I consider a must if the staking is questionable. Mine became wiggly after about 1000 rounds.

If you're going with a skeleton hammer, the beavertail is mandatory. It enables a super high, super comfortable grip anyway.

If you're not carrying it, that should be enough.

Recap:

-Beavertail
-Dovetail front sight
-Trigger job
-Springfield supplied parts


ETA: My milspec is plenty tight as is. I personally wouldn't bother with slide to frame tightening, a little tolerance is good for reliability.

I like an extended thumb safety, non-ambi, but then I carry my 1911 and it's just fast to sweep it off.

Leave the milspec guide rod and plug. No need to complicate the takedown unless you like the look or the added weight up front.

There really is no need to switch out the short GI guide rod. They are every bit as dependable as a long guide rod and make take down much simpler.

I like the slightly extended and narrow safety pad on my old Ruger 1911 and my Colt Combat Elite. I'm also perfectly comfortable with the GI type on my RIA GI. Personally if I were sending the pistol in for custom work I would spend the money on a new safety but it's not necessarily a must do either.

GI hammers and grip safeties bite the snot out of me. So upgrading these two would be a must do for me.

As said, shoot a few hundred rounds through it first to see if it needs warranty work and it'll also give you a better idea of what you would want to change.

That was another question I had.  I noticed on their price breakdown it says "Fit factory skeletonized hammer…. $50"  Does that include the price of the hammer AND labor?  I wasn't sure if these were just labor prices or they included the parts as well… also with the beavertail grip safety, if $100 is for the labor AND the part or just the labor.

One more question, the Defense Package is says "Tuned 4 .5 lb . trigger"  Do they tune my trigger that came in the gun or do they replace it with a totally new trigger and tune it?

another thing to consider is removing springfields stupid ILS lock. Can be done by a layman using drop in parts. Either get the replacement Main spring housing group from ed brown, wilson  ect or you can go with the magwell/msh combo

First thing *I* did on my Mil-spec was replace the sights. Can't hit what I can't see well. Then the trigger was next, followed by the barrel last. I changed the barrel because I wanted the best accuracy I could wring from the gun.

For those suggesting a beavertail, why not buy a model with this already on the gun?

Probably shoot it first and see what you don't like or want to improve on

Go ahead and do some shooting with it as-is first, then decide what you want to do with it. For the type shooting you are talking about, I doubt I would do anything to it. If you wanted to add stuff, it would have probably been better to get a "loaded" model or a Range Officer model.
I own 2 Colts- a 9mm lightweight Commander, and a 70 series Gov't 38 Super. I had a Commander 45 that I traded even for a Springfield Trophy Match model, and have never regretted it. It is a great shooting pistol.

The Mil-spec is a great gun as it arrives from th factory. I think you should shoot it extensively. If you want to make changes after that, go for it.

Before you change anything, run a few hundred rounds through it. It will give you a better idea of what
you might want to change.

I had a beautiful Mil Spec that I sold to my buddy when .45 was scare and expensive, been regretting it ever since! At least I still got my MC Operator lol. Anyway I recommend you shoot at least 1000rds through it first to ensure proper function and reliability and to get a good feel of a stock gun if you're new to 1911s. If there are any issues with the gun they should show up during the "break in" period.
The main thing I would change out is the sights for something like 10-8 night sights.
I got medium sized hands so hammer bite isn't an issue for me but if it is for you a beavertail upgrade is a must. Please leave the USGI guide rod alone, full length ones do not provide any tangible improvement, only makes it harder to disassemble the pistol.
If you plan to practice shooting both sides, an ambi safety is great but even a standard safety can be manipulated with your left trigger finger easily.

Meh, go all the way. I like the mil spec look, but get hammer bite like a mofo.

That picture may have just cost me some $$.

They are a good pistol completely stock for your purpose, anything that you do to it will be more "comfort" modifications than actually improving the gun itself. Having said that, I recommend front strap checkering, if you can get the front strap cut just under the trigger guard for a more comfortable high grip, and better sights. I also recommend a better set of grips than the black plastic or cocobolo grips as both of those are not great when my hands sweat.

If for some reason you absolutely decide to change out the guide rod, get a one piece as the 2 piece rods do have a tendency to catch the recoil spring between the pieces. GI length is fine. Other than that, my only other recommendation is good mags. Watch out for a few though, as the mag length were the slide stop engages on an empty mag can be different causing the gun to not lock back when empty or to not close when a mag is inserted. This can be fixed sometimes by filing away a little on the mag. Chip McCormick Power Mag and the Power Mag + both in my experience would need the mag shaved down about .01" whereas the Shooting Star Classics are perfectly fine.

Kind of my question on the whole premise of buying the mil-spec vs a loaded or the like.

I did the same thing 10-15 years ago, bought a mil spec and had it torn apart & rebuilt with better sights, hammer, trigger, sear, extractor, beavertail,  blah blah blah.
I would have saved myself at least $500 buying a factory gun with what I wanted already on it.

Because tinkering is fun.
I loved building my MilSpec into the pistol I wanted.

These are the changes I made to mine:

C&S 4.5lb Hammer Set (sweet).
10-8 Rear sight.
EGW Custom Thick barrel bushing & plug.
VZ grips.

Done