For gaming I'd go with the i5. As of right now games don't demand the cpu to be overclocked, some benefit from faster speeds. For those now several years into ownership of older i5's, overclocking is reducing the chance of bottlenecking with newer gpu's. Ht isn't completely useless, but it's not a guaranteed performance increase either. Some people gaming with i7's opt to disable ht and in some situations ht can reduce performance rather than improve it. You could go either way since they're priced similarly, both will run games well but the xeon's essentially a higher priced locked i5 with ht.
Each person has their opinions of which is better, I don't game with the integrated graphics but I use my pc for more than gaming. If my video card decides to crap out tomorrow, I'm not stuck waiting on a replacement before my pc is functional again since I can switch to the igpu. The xeon doesn't have that in the 1231v3, to get a xeon with igpu it's almost as expensive as the 4790k.