Yep, the Z77 and the i5 3570k are both for overclockers. Any motherboard thats a h77 is fine. AsRock has good motherboards and the bang for you buck is pretty good with them. As said above, a i5 3570 or even an i5 3470 would do you just fine.
No there will not be a disadvantage. The board is just higher quality and the 3570K is just the unlocked version of the processor allowing you to overclock. If you plan on this being a long term build then a z77 and unlocked processor would be the best bet because you could always overclock in the future.
Although if you plan to upgrade at some point then its pretty much pointless and would be wise to just downgrade and save the extra cash.