I'm not familiar with the heat output of a Phenom II, but that's the best heatsink on the market. The downside is that because of it's 100% copper construction, the thing is heavier than any heatsink should be so making your own extra support for the heatsink is strongly advised.
A couple of things about that heatsink:
1) You should consider lapping it. Thermalright's heatsinks are awesome, but their bases aren't so much.
2) The TRUE benefits from higher CFM/static pressure fans. Going with 38MM thick fans isn't a bad idea.
If you don't want to spend that much, the regular TRUE is a cheaper alternative.