Honestly, the most painful, but easiest solution, is to run it at stock and see if you have problems. After that, OC each component to its max and see.

A64 OCing is set up rather nicely, you always have dividers and multipliers to OC one component moreso than the other.

Example:
I've been having HL-2 crash issues, with a prime-stable 275x10 3200 winnie rig, and the culprit seemed to be the video card, so I was about to RMA. I dropped my OC by 50 mhz, haven't seen a problem since.