Hello all, I am new here and new too rifles, I'm good on handguns. I have a Rockriver entry heavy barrel with Daniel Defense rail on it, shoots great, and I have a S&W M&P 15 good rifle. I want build a 6.5 Grendel. I did some research and know a little stuff. I want something on an AR platform for distance. I wanna get a mega machines upper and lower, 20" or 24" Alexander Arms barrel and bolt, magpul stock, rockriver trigger, weighted buffer, troy industries rail handguard. How does this sound and where can I get good prices on parts.