With as much as $2000 you're going to get less value for money spending it all on a top of the line PC. You get less and less value for money the higher you go above the sweet spot.
So I would say go for an Oculus Rift with a good PC alongside it.
jaslion :
https://pcpartpicker.com/list/YRQTpb
This is the cheapest vr ready build. Of course I can make it better by adding another 8 gb of ram and a better motherboard that has more ports available. But this is a guideline btw if you don't like the case pick something out that you like that is just a placeholder atm.
That's not true, that's way over the minimum required for VR. Doesn't mean it's necessarily a bad build, but you can definitely do it much cheaper than that.
But there are a couple problems with the build anyway - the low quality power supply and the single-channel memory.