On Asus boards a pair of 1gb Kingston DDR400 dimms would go well. For a look over of both NVidia and ATI driven cards in the $60-$150 price range,
http://www.mwave.com/mwave/Deepsearchdd.hmx?UID=&CID= Here the preference on ATI models cards speaks for itself. Where the response will probably come from someone pushing the 7900 GT or another NVidia driven card with a large price tag as well. The older ATI X850 and X1300 models looked good while some may suggest the NVidia 6800.