A noble pursuit to be sure. I have three hours of television from the early 1980s that I found on a torrent, but I have a funny feeling you have it already. It's a CBS Saturday morning broadcast, complete with the short-lived Peanuts cartoon.
I like the size and design, but it is kind of a cheap system, designed to Coleco's penny-pinching standards. I wouldn't pay $40 for one, but then again, I didn't have to... I think I found one at a yard sale for five dollars back in the 1990s. My sole regret is not being able to mod it for composite video. I mean, I kind of did, but the Gemini's TIA knock off doesn't seem to be a perfect match for the official chip in an Atari 2600, and because I could never figure out the proper pinout, the picture I got out of it was... less than optimal. Someone has since posted an official schematic for the Gemini. Maybe if I ever get it back from MI I'll take another stab at it.
My understanding is that the ColecoVision expansion unit is essentially an even further pared down Gemini without its own power supply and A/V connections. All of that is supplied by the CV itself, but can be added to the expansion unit if you wanted a standalone system.