I have never really reloaded anything myself.  I used to sit at my grandfathers side while he did it.  I have his old manuals and things.  I have a couple of his old single stage hand presses.  1 is made by Lee, I think.  The other, i'm not too sure.  Old stuff, for sure.  
I'm 49 last November.  This was when I was 13 or 14 yrs old.  He passed about 10 years ago now.

He was into reloading for accuracy.  I am interested in saving money and reloading en masse.  I probably am about 10 years too late to start.  Salad days are over, I'm sure.

I have noticed that the Square Deal presses come adjusted from the factory for whatever handgun caliber you purchased.  Is this truly adjusted, or kinda sorta close?

As I would want to eventually get to rifle rounds as well, I am looking at the 650/750 line of presses.  

Is there anyplace that sells the caliber conversions already set up?  So, I can just swap the dies, make sure the right primer are loaded and go?  I'm not trying to punch all my rounds through the same hole at 1000 yards.  I'm happy with factory ammo accuracy.

You need to learn how to set up the press.  It is part of the process, no matter what kind of ammo you are making.  This isn't overcomplicated and should not even be a factor for your consideration.  It is part of the process.

I still do rifle cartridges on a single stage press.

I think the square deal single pistol caliber press would be a good idea then just stick with that caliber --as in pick one pistol caliber and not four or five.  I didn't do that so I have a 650 and plates with dies for several pistol calibers. I really wish I had a dedicated progressive for each caliber instead of changing plates and parts.  Loading for pistol calibers is less complex than loading rifle calibers.  Pistol dies come with Carbide Sizer dies that don't need lube. Rifle dies must have lube.

Rifle cases:  example Military type crimped primer 5.56 need de-primed  ( primer may have to be beaten out using an acrilic hammer and deprimer rod because most other rods will bend)  primer pocket cleaned, primer pocket uniformed, primer pocket chamfered, primer pocket swaged, now it's time to trim the length of the rifle brass to the correct length then chamfer the sharp edges.   Then we will re-size the brass.  Seat a new primer paint primer sealer over it.  Measure the powder charge and put it in the case.  Seat the bullet to correct overall length.  possibly a light crimp with a factory crimp die.  Your done.  

With pistol brass I still resize and de-prime it single stage clean the primer pocket install the new primer then run it through the progressive but I would be fairly comfortable doing the whole process in the progressive and just skip cleaning the primer pocket.   So pistol calibers in a progressive press make a lot of sense.  The slowdown comes from all the prep work to get rifle brass ready to load unless you are loading new brass or really good new brass like Lapua.  A motor driven case trimmer and a electronic powder thrower like RCBS is very helpful.  But anything can be loaded on a single stage press you just suffer having to adjust the dies each time and that usually cost you a piece of brass or two. Horniday has a way around that " Lock and Load"

40S&W  I carbide resize then full length resize pushing it all the way through a special size die.  The easiest to load are revolver calibers.
If I knew .... what I know today I would only load   45-70  .308  375H&H  and pistol  44 mag .357 mag  and just buy loaded ammo for anything semi auto.

Keep in mind that if your time is worth anything its not cost effective to load ammo that is not expensive like 45-70 and 375 H&H.  The other reason to load is to get something that cant be purchased like 190 gr Sierra Matchking in a .308.