With an i5-4460, you'll be able to get away with a 1070 without bottlenecks if you're performing at 1080p. I'd suggest either an EVGA or ASUS brand of this card.
The only card that comes to mind right now size wise is the GTX 970 mini (or its counter part from the red team, the R9 Nano), but I can't tell whether they are capable of handling VR.
The most obvious choices would be any 480 or 1060, both cards claim to be VR ready but of of course these are the weakest ones to claim this. your CPU is important as well which you didnt state
With an i5-4460, you'll be able to get away with a 1070 without bottlenecks if you're performing at 1080p. I'd suggest either an EVGA or ASUS brand of this card.