I have a Pro and a One X and I'll say this, when it comes to fighting games there are very little I any graphical differences, too much depends on keeping the game at a solid 60fps so no studio is pushing them to their limit. I have Injustice 2 on both the One X and Pro and they look pretty much identical, I also have MKX on both and because that game wasn't enhanced for either mid-gen console the PS4 version actually looks better, it's just cleaner. There really is no reason to buy an X1 over a PS4 unless you really want Gears or Halo, MS is in a bit of a mess right now with their first party studios, they've purchased a few smaller lesser known studios and will be building them up but that's going to take years to pay off.
Personally I like the DS4 more than the X1 controller, I also liked the 360 controller better than the X1 controller, the build quality was just better, the one that came with my One X wasn't put together correctly and the replacement I bought has a shoulder button that sticks, it just feels lighter and cheaper overall.
I think Sony's controller is much better for fighting games, the triggers suck on the X1 controller for fighting games and the d-pad isn't as accurate IMO. It's up to you, everyone has their own taste but as a guy who's always been a mutli-console owner who preferred xbox over PS up until this gen I'd say stick with the PS4.