I ordered a Gigabyte GA-X58A-UD3R from Newegg. After some reading, I find that the board is relatively low-priced ($209.99) because it only has an 8-phase power design, as opposed to the $289.99 UD5's 12-phase and the $349.99 UD7's 24-phase. I don't think I'll be overclocking the CPU (a Core i7 920) but I will be running it at 100 percent utilization 24/7 with BOINC and Folding@Home. I'll probably be looking to upgrade the CPU to a six or eight-core in the future.
I'm wondering if I'll benefit from the 12 or 24-phase power design, and whether or not it's worth the extra money, especially for the extra chipset and voltage regulator cooling of the UD7.