As far as movie stock, that could be interesting, Kodak still makes 16mm Double perf stock but there are minimum orders required. "International Film" does stock it, as well as re-spooling regular 8 on the correct spools. Perhaps he would be interested in working with you. For regular 8 and super 8 edge numbers are not an issue, in 16mm I am not sure how many folks are doing strictly digital editing and would need the KeyCode bar codes. the older stinbeck style editing can still work with the mechanically created numbers.
Most of the movie stock sold today in 16mm are single perf. _ one money making idea might be to slit and perf regalr 8 from someone else's movie stock. of course for maximum efficency you would have to find a maker willing to sell it to you unperfed so you could do the old 32-35 thing.
My guess is the cost of converting to KeyCode, as well as cheapskates like me diverting 35mm Negative to their still cameras is what discouraged Ilford from reintroducing movie stock after they re-organized.