Exactly which sizes of Roll Pin Punches and Roll Pin Starter Punches will I need for an AR15 build, assuming I'm using a stripped lower receiver and parts kit?  

I'm just starting to acquire the tools for the build, and noticed that Brownell's sells individual roll pin punches and starters.  If only a couple of sizes are needed, I'd rather buy just those than a set of 7 or more.  

Also, I'm looking for an armorer's or barrel wrench.  Is there any consensus as to who makes the best one?  I seem to recall reading a year or so ago about one to stay away from but I don't remember which one it was.

I use a 1/8 punch for the trigger guard roll pin and the trigger/hammer pins.  Then I use your garden variety flathead nails for the the bolt catch roll pin.  I can shave down nails with my dremel too to get the right size if needed.  Then after I'm done with them I throw them away.  I don't want to invest in a small diamater punch that's liable to bend or break.      

Also, be careful about choosing you lower parts.  I've had good experiences with RRA, whose roll pins are easy to get into place.  But I've purchased replacement roll pins from Model 1 sales and they were slightly oversized.  These were a bitch to work with, to the point that I quit and threw them away.  But not after an hour of working with them and scratching my receiver around the roll pin holes.    

As far as wrenches go, I've used the DPMS wrench for all my builds and found it adequate. I did recently acquire an Oly wrench and, I have to say, the Oly wrench appears much superior.

lower receiver assembly has a list of all the recommended tools

OK, the lower receiver assembly instructions that the link above led me to says I'll need only the 3/32", 1/8" and 5/32" roll pin punches, and I assume the same size starters/holders would come in handy, too.  

Are there any other roll pins on the rifle (like in the upper rcvr, butt stock, etc.)that are a different size than those three that are used in the  lower receiver?  If not, I'll probably be better off buying just those three.  Roll pin punches are a pretty specialized tool; I'll doubt I'll ever need to use them for anything except the AR15 build(s).

The gas tube roll pin takes a 5/64" punch if you cant find one you can use a 1/16” punch.