I was facing the same problem with VR and Apple when I was woorking around in the development of making an 3D room in Cinema4D combined with VR. VR is not simply only gaming. VR is everything soon. But, not with Apple (oculus). Oh, i forgot. Apple is making their own VR headset. So, maybe you have an Apple Headset in the near future, but with more than 3 years very active development on the PC side, i think Apple is missing the boat with this.
If you want to go hard with VR, sell your mac pro and replace it with an awesome PC. Some here say, an Mac Pro last longer. But thats a weird statement. VR = PC at this moment. Not only because VR needs gaming power, but also because Mac is lacking power right now. Its a shame that gaming systems are so more powerfull these days than an heavy configured Mac machine.
Or go for console (PS4) when you dont want to leave OSX / Apple and only play games.