With the help of this website, I managed to complete my first "build" of an AR-15 which turned out really well.  I would now like to try a build of a 1911 .45 but am completely unfamiliar with all the notable manufacturers of kits and parts.

Like the AR-15, Im assuming their are pices of an 1911 that can only be pruchased through a FFL? (such as the serial numbered portion of the lower receiver).  If so, what are they?

My idea for a build is for a single stack, 4 inch barrel, night sights and a single rail for a tac-light.  I would like something that is not stainless.  In fact, I would love to find a green frame much like Wilson Combat and Springfield offerings.

Anyone who may have some adivse of information sources, please respond.  Thanks in advance.

Frame is the firearm according to ATF.

Caspian is hard to beat for frames & slides.  They sell their seconds & blems under the Foster name.   Nobody sells green frames, they are all in the white and you apply your own finish.  Obviously you can paint a stainless frame green just as well as a carbon steel frame.   As for barrels, Storm Lake Machine makes a pretty good semi-drop-in from what I have heard.    

For parts, avoid John Masen.  Caspian makes a line of parts that are decent without breaking the bank... as do Wilson and Brown.

As Ken Mays said above, the frame is the only part you purchase that has to go through an FFL.  The rest is like buying candy in a store.  Pick your own flavor.   I have built two using Caspian's frame and slide, Berryhill parts, Wilson parts, Kart barrels, Cylinder & Slide MSHs, etc.    Do a lot of reading here and the other available 1911 forums before you start buying parts.  Have a clear picture in your mind of what you want to build.  I thought I did at one point but changed my mind a few times and ended up with extra parts.  

May have to build a third one now...

Be mindful that putting a 1911 together is nothing like putting an AR15 together.  You will need tools, patience, knowledge.  Buy the Kuhnhausen book (the first volume).

You don't "Build" AR15s, you assemble them like legos.

A 1911 is a world away.

This!

That is the truth but man if done right you get one fine ass piece of machinery!!!!

I just bought a DS railed frame and will have to fit my slide to it.  Suggest if you can that you order your slide and frame already fitted.  Take a look at Brownells.com and have your LGS order the frame and slide.  This will save you headaches ahead of time.  Then there is the issue of fitting the barrel and trigger group to name a few.  Some guns are cheaper to buy ahead of time than assembling them yourself.

CD
relearning patience

Unless you have the proper tools, you will likely not get the results you are looking for.  Buy a base gun, and add to it.