Comparing the Sabertooth and the P8Z77 V Pro,the P8Z77 V Pro is the better one I'd say.This is because,you'd need to go for the Sabertooth only if you really care about looks.
The V Pro has little more features than the Sabertooth or say both of them has almost similar features.It's just,that the Sabertooth has that Killer looks,which the V Pro lacks.And the heatsink of the V Pro should be good enough.Just make sure your case has good airflow,and you can overclock as well with that board if you want.
And about the Pro version,you should go for the V Pro only if you're not very tight on budget.They do have some extra features,though wouldn't be necessary anyways.They are,
First is,ASUS Q-Shield-Easy and Comfortable Installations
The specially designed ASUS Q-Shield does without the usual "fingers" - making it convenient and easy to install. With better electric conductivity, it ideally protects your motherboard against static electricity and shields it against Electronic Magnetic Interference (EMI).
Second is that the Pro has 2 onboard USB 3.0 connectors and the regular model only has one which only matter for front panel connection.
Last is the Pro has four system fan headers and the regular one has three stystem fan headers.
So,if you don't care about these little things,I'd say the regular version is the best choice.
Hope it helps...