Make sure you really want the 32GB SSD. It's either a really small C drive for boot (yuk) or used for SSD caching of IOs (yuk). Net, I wouldn't want it in my system, but some people would. (I do own several SSDs, but I use spinning disk in my gaming system)
HD7770 is a respectable card, costs $130. The CPU (i7 3770 @3.40GHz) is really strong & expensive $300. Most gaming builds would move to a cheaper CPU and a stronger video card. Your system is not really balanced well for gaming. But it will game nicely.
12GB DDR3 is a lot. It's not that expensive, but you won't see much value today above 4GB so the 12GB is a lot of future proofing. But memory is cheap.