6600 GT....never get any "LE" card from Nvidia. "LE" stands for "Lame Edition." The 6800LE gets you about the performance of a 9800XT, only with Shader Model 3 support.
Yeah, you will be way better off with a 6600 GT. If you want a 6800, go with the 6800 GT. With Nvidia, always get a card with a "GT" or "Ultra" suffix. Avoid cards with "LE" or no suffix at all like "6800."