how are you planning to beef it up? by overclocking? you didn't mention the mobo and I doubt you'll see any benefits in overclocking that A4 to compete with a 1st, 2nd or 3rd gen cor i proc.
whatever you do it'll bottleneck. even hybrid crossfire is pointless. the APU's were designed as a good niche caterer for business' and HTPC's with lil or no gaming on it.
start from scratch. You'll be glad you went new for a gaming rig.
* btw you may want to take a good
look at the make of the:
PSU and RAM
my 2 cents