I would set it to 8x aa, and 16x af
Basically crank that sucker up. Everything on high. That card's got enough juice to crank the settings up. If you notice a performance slip drop the AA down to 4x.
Overclocking tools can be found here, I don't own a geforce so I can't recommend which one to get, Rivatuner is popular (Rivatuner is what hardware sites use when they benchmark the cards) and so is GeForce Tweak Utilities.
Here is a link to a ton of tweaking and overclocking utlities
I've read that under proper cooling conditions you can take that card up to 558MHz (core) and memory clock of 515MHz safely.. I'd move up slowly at first if I were you..especially with a lower Power supply.
Hope this helped.. Merry Christmas back at ya