Graphic card, updated recommendation desired; future capture card

I would like an updated Adobe Premiere Pro 2.0 graphics card recommendation for use in editing in SDV and SProDVC50 that will not break the bank (<$500?). The card will be used on an MSI K9N SLI, AMD2 4600 mb, 2GB 800 RAM, SATA II Raid 0 from mb. This is a beginner's platform, so I'm just looking for something that will take advantage of the latest technology (last year's?) that will be compatible with Adobe Pro 2.0 now and with the addition of a capture card, as yet undetermined. I've seen a few of each that go from low end to very high end, way beyond budget. Any recommendations for graphics card and/or capture card will be appreciated.