I would grab the directCU (er heard about from reviews and people here, they seem to swear by it.)
Yup, I'm one of them!
To the OP:
I'm running the TOP version and its brilliant so far! My main issue was the temp's (ambient here is around 43-45 deg celcius, so was a big cause of concern!). Load temp's haven't crossed 75 so far, and that's with many demanding titles. It's been running everything on highest settings and the gameplay is smooth.