Differences between mobos and will it conflict with ram and cooler

Hello, I'm building a 2500K OC rig and got a Scythe MUGEN 3 and Gskill ripsaw 2x RAMs.

My question is what are the differences in the following ASUS and ASrock mobos and will they conflict/block RAM slots with the mugen 3 cooler.

ASUS P8Z68-V GEN3
ASUS P8Z68-V PRO GEN3

ASROCK Z68 EXTREME 3 GEN3
ASROCK Z68 EXTREME 4 GEN3

I know that the higher and more expensive models have more connectivities and SATA slots, but what other differences are there including in terms of OCing?

Thank you in advance.