i have a nice kit....not sure on what reciever to get or where to get it, i think i read the PTR91 was the one to get. also worried about putting it together,  no problem welding or anything....but the better option might be to have it sent off if it is not too much money.
also best place for US parts?

A JLD PTR91 reciever from POF USA, and have Jayson at IGF do the build for you.  Add the paddle magazine release.

As far as US parts go, I bought pistol grips, buttstocks, and wide forearms from Top Notch, also have a hammer and sear from them as well.  For a Flashhider I went with a Smith Enterprises Vortex.  JLD also make compliance parts, hammer, sear and a trigger now.  They also make/use reciever, barrel and trunnion in their guns.  I think that the Navy style lower from JLD is the one from Top Notch.

how much $$ we talking when its all said and done?
all i have is the kit