I bought a 6.8 Rem SPC, it is on a Rem 700 S/A platform. I bought it because it was a good deal to start, second I couldn't make up my mind between building a 6mm or a 243. Am very glad I went with the 6.8 Rem SPC it is a kick A$$ round. Will be getting a 6.8 upper for the AR-15 in the near future.
And as for the forum (the guy that built the 6.8 showed it to me). Looked like the place to be.