Thank you for your work on the Leap plugin getnamo! Although I abandon the idea of using Leap in my game, it still helps a lot while Leap pretty much put no resource in UE4.
I hope you get you Vive quicker, I know a friend that pitched his prototype to Valve and get Vive Pre on the same day as my CV1. So if you pre-order really late, you might want to consider this or the UE4 grant program, Epic also have 500 Vive Pre to “worthy” developer. And I think you definitely fit the bill with your Leap plugin alone.