Parts sourcing: Prefer things I can find on pricewatch, like to buy on internet. Prefer 50-90$ price range.
Parts Preference: Prefer name brand (Nvidia, ATI) with Linux support. Was considering geforce 9600 gt, geforce 9600 gso, geforce 9600 1gb, pending your advice.
Overclocking: Possible, if card underperforms.
Resolution: Running two heads 1280x1024 and 1440x900
Comments: Thank you very much!
More aboutadvice choosing computer
As long as you have a x16 physical slot (which the server claims it has) then you are fine. If it only runs at 8x, 4x whatever it is ok (the card will run). Only top end cards would be hurt by the bandwidth reduction.
Oh, and for your requirements, 4650/4670, the 9600s, GT220/240, or the low 5000 series cards would all do fine.