The Bear Creek uppers fit my Bushmaster/DPMS pattern lower just fine. 6.5 Creedmoor and 308 is just a different barrel.
For the price I'd get the Bear Creek complete upper and then switch everything to the other folks upper if it didn't fit. Barrel, BCG, rail, and gas system will move over easy.
Unless I'm just building a bench gun the 22" is a lot of extra length and weight to mess with.
My 16" Creedmoor does 850 yds no problem.
Just my thoughts.