Answering your What kind of graphics card question...
Nvidia Nvidia Nvidia. ATI has too many problems, especially with Visual Pinball. A lot of people successfully run the 9800gt series either in 512mb or 1gb flavors. 512mb is the lowest you want to go. In fact, I would probably use the 9800 series as a baseline. There are a lot of cheaper cards that have 1GB of memory (like the 9400 and 9500 series) but they have a lot few stream processors, lower clock speeds, lower memory interfaces, etc. So I would say a higher end 9 series (9600, better yet 9800) or 200 GTS/GTX series Nvidia card, at least 512mb of memory (preferably 1GB if you want to play some of the night mod tables).