Very few of the good boards will accept both DDR2 and 3. The ones that do are pretty limited in overclocking features (P5K-C is the only one i can think of off the top of my head).
Look into the Abit IP35-Pro, its a sleek, stable more refined board.
The Maximus is sposed to be good, just OTT imo. More options in the bios that the old SLI-DRs just confuses and theres far too much heatsinkage on there, again thats my opinion on it though.
Keep an eye out for the Lanparty DK models to, they're also shaping up rather nicely.