So I got a desktop computer. Got it for $250, but the GPU died after I bought it and the seller replaced it with a much older one that's unfit for gaming. I'm looking to replace it with a new GPU that's capable of high-end gaming and won't be bottlenecked by the CPU. The specs as it stands right now: Intel Core 2 Quad Q9400 @ 2.67GHz HP OEM motherboard 8GB DDR2 dual-channel RAM Nvidia Quadro FX 3450 256MB GDDR3 750GB SATA2 HDD What type of graphics card would I be looking for with this setup? Also, are there alternative ways I might be able to overclock this thing (as this HP mobo doesn't have clock settings in the BIOS)? Thanks in advance.