video display help please

[drunknbass]

k so when i was setting up my os x86 i had to do some hacking to get my x600 graphics card to work and display my res (1920 x 1200) , well now im using osx as my main os and starting to get software and will soon by doing my video editing on it. but i noticed a problem. if i play video full screen it lags and seems to drop alot of frames. i dont think its my pc cause its a dual xeon 3.6 with 2 gig ram dell 670 precision workstation

i know my graphics card sucks. maybe theres something i can do to make it work at leaast as good as it should till i buy a new card, and also what 300-500 video card is supported by osx 86 where i dont have to hack at stuff for a week to just get it to display right? i want a card that will actually perform good like it would on pc