See the page for cinema rig configuration.
I have long been in the diy camera movement. The above camera comes from a company that followed what we were doing. I have been considering doing a camera below $500, but this require substantial expertise, money, time and commitment. I have also been waiting for parts. With just 100 people you might get a hybrid camera made under $1000, even under $500, that would record near visually lossless to lossless (which is more tricky concerning pricing). You would get more manual control, maybe better image quality, and better compression quality.