well for the most part a prebuilt pc will not be able to overclock. you can wait for the bulldozer but who knows if it will be better?
You could build a decent pc off of $829. I can't answer the question of should u get a pc or a ps3. I personally would get a ps2 but I like jrpgs. here my stab at the 829 budget. sometimes machines from best buy can use some subpar parts
total 844 (no tax) b4 rebates and shipping. you get usb 3.0, a better mobo, better cpu, probably slightly better ram, more hard drive space, a cooler case (you could shave off some $ there) and longer warantees. You dont get a computer right out of the box, a wifi card, a media reader.
Get the pc...if u want to play fps shooter games...
Or else go for ps3 if u..like to adventure/racing type games..
But u can play all types of game in a pc..but u can't on a console very well
and last reason ..u can upgrade ur pc..acc. To games
but what if a new console hit the ..market then u can't play ur older games..i.e. U can't play ps2 games on ps3
but u can play ur old games on pc ...it means ur previous buy wouldn't b a waste...think abou it