rift is too overrated, i'd go with vive, or something else that use IR tracking to avoid delays causing by motion sickness.
something like rift+trackIR or similar technology
head mounted displays were real DECADES ago, the only difference is - now they can be small enough and cheap enough to produce massively, and there is a demand for it
on the subject of virtual reality, i'm very positive that messing with surgeries on open brain are not required, as most stuff can be wired on neck