EXT64
Splendid
OCing your graphics card is pretty safe as long as you keep an eye on your temps. If you set a graphics card too high it will start artifacting. I don't know how well your card will OC, but it's worth a try. My old 6800's were awesome OCers.
Processor OCing depends on the motherboard/bios and most prebuilt systems don't allow OCing.
Processor OCing depends on the motherboard/bios and most prebuilt systems don't allow OCing.