This comparison is very interesting because all processor are very similar however there are some things to take in consideration.
The Intel® Core i7 4790 is a processor intended for desktop solutions and the Xeon processors are intended for Server Solutions (most of the times).
If we take a look closed to these processors, I would say the best option for you is the Intel® Core i7-4790 processor since it has the same specifications as the Xeon but it also includes other technologies that at this point you say you will not need them but in the future you could use them.
Besides this, the Intel® Core i7 comes with onboard graphics which in the hypothetic case the video card you will use fails, you still can use the onboard graphics.
At last but not least, the price of the Intel® Core i7-4790 is cheaper than the Xeon processors. I can assure you that you will get the best performance ever using any of our processor but in your case, I think the Intel® Core i7 is the best option.