when you buy a motherboard you need to consider the other components first and then decide on what motherboard to get to support those components... for instance are you going to be building a intel rig or an amd rig? do you want ddr3 or ddr2 ram support? what type of graphics do you need? this will all come into play...
I know that photoshop does alot of rendering so The cpu is important... i would suggest going with an intel processor for that.. ultimately you will get better performance from ddr3 ram but that is not a necessity you could still do great with ddr2 ram and onboard graphics should be ok unless you plan on gaming in the future... good luck