I know about the newer cards out but I really need advice on the following. ATI X1800 XL or Nvidia 7800 GT? Or would dual 6600 GT's be better? Thanks for any advice.

Hi Ken, IMHO, a display adapter answer is useless without a mention of the system and - equally important - the resolution in use. It would also be useful to know how you like to use the sim. Hope this helps, good luck and kind regards Jaap