Yeah, no ones mentioned thoguh that BFG cards come pre-overclocked so the card is already when bought, better than the card by another company, and this can usually be pushed even more.
I wouldn't bother changing the processor its good enough
"Well I would switch over to AMD 64. Your processor is 32-bit. I would recommend getting a 64-bit AMD processor, though that would require getting a new motherboard."
You wouldn't be getting 64bit computing yet anyway since the 64bit widnows os has only just come out, and only a few if any programs support 64bit as of yet, so this wouldn't really be an idle change as of now, though in the next few years, it'd probably become more useful as more programs/games support the new function. but no difference would be seen yet
I hope this helps