Alternatively you could go wait for more detailed feedback on the new ATI HD5xxx series (people should have analyzed each and every little aspect of it and post it on the net within a few months or so) and get one of those.
Sorry lol. Anyway, if all you have in store for it in Linux on it and don't want to run heavy games on it in the mean-time (and also want to spend less so you can spend more on the complete new build) then just get the cheapest card you can find i.e. ATI HD4350 or Nvidia 9400GT. They're actually not too bad, on minimum settings on medium resolutions, Crysis is fully playable on bothits a socket 939 sli motherboard so i do have one pcie x16 and 2 pciex8s and i was asking for one that would stay in this system becuase ill be putting linux on it and running that. oncwe i get the money for a new system and i was oping not to spend to much for a new card incase the 7600gs goes out. ive had some issues but nothing major yet. im just asking as a precussionary measure incase something does happen