HP e9180f desktop,Intell corei7 920 CPU,9Gig Ram,Windows 7 Ultimate 64bit OS, NVIDIA GeForce GTS250 1 gig card currently,PCI e 2 slot,one 6 pin power plug,Delta DPS-460 DBA PSU. Looking for advice on the highest quality used gaming card I can install with my current PSU and CPU. Seem to be lots on eBay etc here in Canada.