Rift Skyboxes/ clip distance

I was messing around in my game that uses large distances of view in deep space and I ran into a couple issues. One is that I can't seem to increase the clip plane on the OVR cameras past a certain distance. Is this something that needs to happen after the game starts? I ask because I wanted to cull a layer from one of the OVR cameras and the only way I could do it was to run a script when the game started.

Also, The skyboxes seem to be a real hassle so far. I'm not an artist, so I can't paint a skybox myself, nor can I seem to convert a skybox to Rift-compatible by transplanting the materials. I can always see clearly the corners of the box itself when I do this. Does anyone know of some good pointers on doing this, or know where one can find a space-themed rift skybox? Thanks for reading.