Hey man., you should go for Z77., i guess your price point is under 10k., so you may have other options like:
- ASRock Z77 Extreme 4
- MSI Z77A GD55
For Z68., go with d6bmg recommendation if you have lil. up budget or: MSI Z68A GD55 (B3) and Z77 performs better than Z68 and will outperform with IVY bridge CPU's if you plan to upgrade later