im getting an abit a8n sli board...now, i know geforce card is recommended, but could i be able to use a single Radeon and get away with the same results?
Well, seen as you have an SLI board it means you can stick two matching SLI cards in the board to get nice performance, or you could stick a powerful singular card in such as nVidia 7800 GT or GTX, or an ATI X1800.
All three choices are extremely powerful, and relatively expensive. If money is an issue however I'd go with either a single 6800 GS or two 6600 GTs.