bownarro1,
You won't be disappointed with J&T. They are great to deal with and my 24" bull barrel shoots 1/2 inch groups easily.
Rooster,
Barrel length, I know that my 16" is a lot easier to lug around all day than my 24". I'm thinking of building a new one with a 20" Krieger and a carbine length gas system. I saw this out of John Feamster's book. "Black Magic: The Ultra Accurate AR." He says it is light enough, and like all AR's we're discussing, extremely accurate. I'll let you know when it's done, but ultimately, a 16" will kill just as reliably at 250 yards. I like low rise best, but I think it's more about personal preference. I do recommend a GS-1 Rail so that you can position your scope far enough forward for proper eye relief. I like the tip of my nose to touch the charging handle.
Ed,
1:8 twist for heavy bullets up to 72 grains or more. 1:10, 1:12, 1:13, 1:14 for up to 55 grains. 1:8 will work fine with light bullets, because you can't overstabilize a bullet, but you might shoot the barrel out faster because of increased muzzle velocity with lighter bullets, increased heat, etc... NM trigger, single stage or two stage? For paper targets, a two stage is great, not so much for critters. Can't go wrong with a JP.
Blake