P8Z77-V if you are planning to SLI. The sabertooth looks nice but I don't think it offers a significant improvement compare to other boards in the configurator that support SLI even if you are planning to overclock your cpu.
I'm getting the Sabertooth in the build I'm getting but I'm getting it for the 5 year warranty and the perks of the board such as protection against dust, protects your board from getting even hotter from the other components in the build. And you can take off the thermal Armour if you want it isent a must.
And if you watch some reviews it actually keeps your board cooler but if you take it off it gets alot warmer.
Chriso, I would check if you do actually get the 5 year guarantee with the sabertooth Z77.
The warranty thing is a bit of a hazy issue. I have a sabertooth Z77 in my recently received computer as well. I believe PCS use some OEM parts with their computers, if so they don't have the same manufacturers warranty as retail parts, therefore the warranty lies with the system builder (so up to 3 years depending on what colour warranty you ordered with your machine)
This is certainly something I'm aware of with the western digital caviar hard drives. I tried registering mine on the WD website and was told I couldn't as they were OEM drives, and it says their oem drives come with no manufacturers warranty, so the warranty will be the duration of your system warranty regardless of whether its a caviar black or green.
I don't know if this is the same with the motherboard, but it wouldn't be right to automatically assume you'll get the manufacturers duration!