To create a custom "Unofficial Guide" Raspbian Distribution, here's some info:
I think the easiest thing to do is to get a microSD card, install it in your Raspberry Pi, configure it, then sell the configured microSD card at cost.
This 32GB Samsung EVO is $11.
This el cheapo 4GB Kingston at $5.68 might also work:
If you do it a few times, you'll have a fully functional configuration for using the THETA USB control with a Raspberry Pi. Then, after you have a good setup, you can build your own distribution.
While your at it, you can test a few different batteries to make sure that the battery can power the Raspberry Pi AND the Raspberry Pi can power the camera through the USB port.
If you can get one other person interested that lives near SF, you can throw a little configuration meetup where you build the SDcard and test the Raspberry Pi with the THETA in different situations, like long-term timelapse.