You're in the overclocking section so I'm guessing you want to OC the CPU.
Currently there are no good 945 motherboards that will overclock like the 965 and 975 chipsets. Right now 945 and overclocking just don't mix well together but give it some time. Once C2D becomes matured you'll see decent OC boards using the 965, maybe 975 at lower prices.
If you don't plan to OC, then a 945 board will suit most people just fine.