I'm a "newbie" to the camera and film industry, but I have an extensive background in electronics and fixes (hacks), and hope to be able to contribute to this community.
I do YouTube videos as an activist to help others escape being damaged by a cult that I survived being in for 50 years before escaping.
I've decided to purchase a Cannon brand of camera strictly because of the "fix" that Magic Lantern has available for it. I would like to hear from camera enthusiasts here which model they think will give me the best bang for the buck with ML and doing green screen. Thanks in advance.
You can get a used EOSM for around 150 USD. There are many other ML cameras that are more capable, but at 10 to 20 times the cost, it's hard to say any of them would be a better value. If you want hack it, IMO, the EOSM is probably the best choice; the cheapness means low risk if you do end up bricking it (very unlikely anyway). The touchscreen means there's lots of potential for in camera user input and debugging (for example the lua_touch branch contains an onscreen touch keyboard and interactive Lua console, so you can run stuff and debug on the fly, as well as edit scripts in camera).
If you have some experience with ARM assembly (esp. Thumb-2) and are in for a real challenge (many hundreds or thousands of hours), you might consider one of the new digic 6 cameras (80D, 7D2, 750D/760D). ML has yet to be ported to any digic 6. See: http://www.magiclantern.fm/forum/index.php?topic=13746.msg167719#msg167719