High Quality Video Input Card?

I know theres hundreds of varying quality TV tuner cards around, and most of these can take Composite / S-Video inputs, but I don't need a TV tuner, the digibox can do this. All I really need is a video input card with a single RGB SCART socket on the back. Do these exist seeing as SCART is a European connector? If so, what are my options? Do any of them have MPEG2 encoding?

Thanks

Haven't seen any RGB-in video cards and the US doesn't do RGB, rather component. Good luck finding one less than half a grand.