Color negative is probably the way to go, or b/w negative because they are most likely available at reasonable prices. Color negative and color reversal are totally different film stocks and processes. Most black and white reversal films can only be developed as reversal but most black/white negative films can be developed both negative or reversal if you want. I would look for negative films anyway unless you specifically need the film only for projector use and you are not planning to scan it at all
I saw somewhere an example of this kind of stuff a while ago (maybe 10 years ago or so) . Of course you can get clear film (just get perforated base material so that you don't have to mechanically engineer a feasible perforating machine) and coat it by yourself. The coating process is actually the most difficult part, not the chemical compositions.
And the gelatin is very difficult to get to stick to the film surface so that it would not peel away when it dries.
probably it will cost a lot more than buying factory made film, but can be done if you have enough time, know how and equipment
making film is complicated and can be expensive. It is possible, but not really for motion picture film uses. There are too many precision requiring steps.
If you want to achieve nice looking footage relatively cheap, just buy modern color negative film for 16mm camera and buy process+scan package for it. Processing costs money, but can be still relatively cheap (like $0.4/ft., including good quality HD telecine).
By going DIY route you won't get the results you asked for in the first post. Period. Manufacturing color film at home is not possible. If some sort of black and white film with its own home brew characteristics (it won't be perfect, it'll have its flaws) is enough, sure, you can dedicate years of your life to this endeavor. You'll need solid knowledge of both electronics and chemistry and you have to be comfortable with designing machines and sourcing parts for them and then building things with your own hands using different tools. In five years you might have some sort of film manufactured, then you'll have to find a way to get it slit and perforated with good enough perforations in order for it to run well in your camera and give you stable image.
If your passion is making films and not engineering/chemistry, I strongly suggest just buying a K3 and some film for it. Shoot it, process it, telecine it and then decide what you'll want to do next.
Buy short ends or expired stock is the only option.
Stock is actually one of the cheaper things because you can get expired stock on ebay. The problem is processing and as I've mentioned before, how are people going to watch it? You can't project color negative and you clearly are looking for low-cost solutions for things, so you can't make a telecine machine yourself out of a projector without making a print first, which is costly in of itself.