mATX is fine as long as you dont need more than a couple of pci cards, most can still handle 2 X SLi, but not with an additional audio card as well.
Asrock Z87M Extreme 4 is a really good value mATX board and probably has a bit better audio than the Asus offerings. If you want a full sized board your going to pay a little bit more.GFX
Most of the GTX760s are all within about $40, i like EVGA as they are good quality and in the middle price wise.Case
If your going to go a mATX board the corsair 350D case is one of the best around http://www.pccasegear.com/index.php?main_page=product_info&cPath=25_961&products_id=23206
If that's a bit exy for a case, Bitfenix make really good quality cases for cheap.
For a PSU you only really need around 500-600W, much more will be a waste unless your planning some serious overclocking. Just make sure whichever one you get meets the Haswell requirements. Corsair TX / HX series or silverstone strider series are both pretty good.
Check this link out for what works on Haswell: http://techreport.com/review/24897/the-big-haswell-psu-compatibility-listRAM
I reckon 16gb RAM would be better if you can afford it, the more mem you have the better and you wont need to upgrade in a couple of years. Get a good brand cause cheap mem if always the first thing to cause errors in a new system. Corsair Vengeance series is good.HDDs
HDD / SSD whatever you like, at least 120gb on the SSD, but thats standard these days.
All of that would come in at about $1,500 or a tad more. If anything the 4770K is a bit overkill for gaming (assuming that's he primary use.) You could save $100+ and go with a 4670K and still have a machine that will smash any game on the market.