I am an experienced Unity GearVR developer, having authored or collaborated with several applications for 360º vídeo visualization and VR games. I have also worked on some Unity3D games, having some of them been greenlit on Steam and/or XBox/PS4 approved.
I have been working with Oculus devices since almost day 1, and with game dev longer than that.
I have been working with clients all around the world for years, I'm used to self-manage and to articulate with different time-zones.
Regarding the project, I can either develop by myself, or bring a small team (artists, game designers, developers) experienced on gamedev on board, it all depends on the requirement. Our individual game/app projects add up to about 5M downloads from 2011 to the present.
As for the milestones, I propose a kick-off fee of 30%, after the payment is cleared, a few days to organize the roadmap and establish requirements, work starts immediately after that point.