Both good choices. If it's dedicated paper, 6.5 CM could be tough to beat next to the 308. If game is involved, I'll take the 308 any day.
You can fling a 190 in a 308 nearly as fast as a 140 in a CM. Windage will be slightly better for the CM, recoil again to the CM favor but down range energy and barrel life will hands down go to the 308. The real question is which of those qualities matter to YOU the most?
Like I said game is almost indefinitely not going to be involved. Also I am going into the Air Force this fall and will not be able to shoot much while serving my time in. Additionally, I understand the reality of having to rebarrel, I just want something that will be ready to stretch out to 1000 yds and possibly beyond when the time allows (and when I'm a much more experienced shooter). Also I like the idea of a lighter recoiling, flatter trajectory, cheaper to shoot with factory ammo gun (.308 GMM is, from my research, about $2-$4 more expensive/20rd box than the 6.5CM Hornady match ammo).
So in conclusion I think I have pretty much settled on the 6.5, but still looking for factory guns. Savage seems to be my best option right now--the only other factory gun I have seen chambered in the 6.5 is the Ruger M77.