need graphic advice

System: intel e6600, asus p5b-e plus, wd 70gb sata, 1gb corsair 6400, silverstone strider 56f. Eizo flexscan m1950 19" (8ms gray-gray)

Im running linux and dont use windows at all. So I dont care about the hype off directX support. The only thing that matters to me is OpenGL support. The only game i play is Enemy Territory, yes its still going strong on the internet. I belive my tft-display is the systems bottleneck. I run it in 1280x1024 resolution. So what is the maximum fps that i can get out from the display using this resolution and what card would fully fill my needs.