This is easy. If you want to overclock, get a 4770k, if you do not want to overclock, get the Xeon.
The Xeon is GREAT for gaming and is NOT just for server use. It can use ECC memory but it is NOT required.
Why are these two the only selections? Are you aware that there is a Xeon e3-1230v3 that is LGA1150? There are also e3-1240v2/v3 and e3-1245v2/v3 that has integrated graphics. Also, the i5-4670k is about the same price as the e3-1230v3. The 4770k is $80-100 more.
So if gaming is the main concern for this build, AND you want to overclock, my vote is i5-4670k. If you just have extra money to spare, the i7-4770k is unmatched. If you don't want to overclock, absolutely get one of the Xeons. The e3-1230v2/v3 are great values.