My C100 came with a decent instruction manual and has an ssr output. I havn't tried to wire it up yet but the instructions show which terminals to use. I will be controlling my boil with a pwm, and controlling my mash temps with the pid in a single vessel biab system with continual recirculation during the mash.
I think a lot of the people on ebay selling this stuff knows verry little about it, and the reason why they all have the same description is because they are hooked up with the same company that sells it. Probably all they have is a computer and the products are shipped from a warehouse somewhere. I asked one seller about combined shipping and he said no because they were shipped from the warehouse.
I hope I can make this thing work, it will be a cheap controll panel.
edit after further study of the instructions I dont have an ssr relay and my wireing diagram dosn't match the one on the rex website.