"Some benchmarks" is very, very vague. I will need some clarification on what exactly you want to compare. All I can say right now is that some i5s like the 4670K can be overclocked, which is the only thing Xeons can't do, however overclocking is generally useless for gaming as any modern-day CPU will do pretty well and won't even reach its normally clocked limits. That aside overclocking can significantly shorten CPU lifespan and if it's done wrong can outright fry the CPU. The Xeon also has 2 MB more L3 cache, which can be either good or bad depending on the situation - the cache temporarily stores data that is repeatedly accessed, so if you have a lot of that repeatedly accessed data, the Xeon will access it much faster instead of having to look in the RAM for it, however if that repeatedly used data is very little, the bigger cache means that the Xeon might or might not need some extra time (an extremely small number) to find the data it's looking for in the cache, since it's bigger and there's more room to search for it. Those are the only differences I could find between the two processors besides the extra threads for the Xeon, the lack of onboard graphics (which you do not need) and the small clock speed bonus of the i5. All this taken into consideration I believe that the Xeon is a significantly better choice because it is basically a high performance i7 that can't be overclocked while costing less.
Regarding motherboards, that's not generally a field I know too much about, but I know that Z87s are slightly older overclocking motherboards, while H97 boards aren't really meant to be overclocked. Since the Xeon isn't an overclockable chip, the H97 sounds like a better and more economic option. A good thing to note is that there are plenty of difference from model to model and I think that Z87s offer SLI/CrossFire support while H97s don't really offer that (I believe? ). I would go with the Xeon and the H97 if I were you. What specific H97 model are you considering?