you might want to consider 1.5v ram as i've heard that ivy doesnt like 1.65v, other than that maybe an msi motherboard as they seem to have the best offerings for z77, if you have the money you could upgrade to a 7870 but thats not that important.
i don't have much experience with gaming at that resolution, but where i live the price diffrence is about 30$, so if you arn't tight on money i dont really see a reason not to.
1. Go with an MSI Z77 G45/GD55 at that price range, it has more features than the Gigabyte and can OC better
2. Go for 1.5V RAM, Ivy Bridge does not like 1.65V, you MUST use 1.5V or lower else you'll be running into issues and such.
3. Any reason for an low profile CPU cooler? You could fit an NZXT Havik 140 in there for a tiny bit over £700, it's a beast of a cooler but it's actually quite small considering how well it performs
EDIT: 4. The HDD you've selected is only SATA Rev.2! Get a SATA 3 HDD