I can throw my $0.02 around I guess. The Phenoms are excellent processors. I ran one of the original bad boys (x4s) when they first were released and it lasted me close to two years before I decided I wanted to upgrade. Now I'm running the x6, and it still is a dream. Finding a motherboard can be a bit tricky with the 125W, but most of them should show their max rating (you might have to visit their website for full specs.)
Personally I'm also running ATI, and have been for quite a while. If you're running AMD I'd suggest sticking with ATI (since it is owned by AMD), but it is not a requirement (just check your mobo)... but ultimately I guess we need more info on your budget.