Z68 Asus Maximus IV Extreme or Z77 Asus Maximus V GENE

Hi all,

Next week i would like to build a new PC.
Im going to use a I7 2600k/2700K, but im not sure which motherboard to choose.
Z68 Asus Maximus IV Extreme or Z77 Asus Maximus V GENE ?
I use my pc for games and video editing, and i will overclock it extreme.(custom watercooling)
The only problem i have with the GENE serie is that i have a Silverstone TJ7, so it will be a small motherboard in a big case.
What should i choose? or pick a different motherboard?

Thanks

Tammo