Thanks for your help guys! So you think the pcie x1 card would provide a noticeable performance boost for the games I want to play?
Also, I opened up the tower again today. It's a Dell Poweredge T100. And it has PCI, PCIE x1, PCIE x4, and PCIE x8 slots. I'm not necessarily set on the two graphics cards I posted above. I've been having trouble finding graphics cards that aren't PCIE x16, though. Do you guys have any other card suggestions besides the ones I've found?