Jason,
Easiest is likely to just use an rpi camera module. Biggest issue may be routing of ribbon cable. We have used up to 12in long cables. You have to shield them so it does not mess with gps. We use copper tape on the cable and then electrical tape over that. Make sure you use a drain wire. Just strip an end of small gauge wire and capture it on the copper tape with the electrical tape. Run the other end to ground. Puts out really nice h.264 video for the price. Should move well over 4g if you keep your size and frame rate realistic. See the emlid docs for example gstreamer pipelines.