A couple of people have suggested BP/Wings, but does the OP dive with a BP/Wing? If not, do you have time to learn how to dive a BP/wing? Are you gong more independent or are you going to be affiliated with a dive store? I started teaching when we were using Horse collar BC's. That meant you had to have a weight belt, weights and a backpack. When I started teaching I was an independent instructor with affiliation with a dive store. We were given a choice of different packages from the dive store and given a line of credit and a payment schedule for a year. I went cheap because I wasn't making any money yet and I had to get going. I had 10 sets to start with. I had BC's (no power inflators), regs (started with regs and spg only , no alt Air source) . Tanks I had 50 cubic foot tanks. They were easier to carry and they had enough air for teaching in a pool that had the max depth of eight feet. This was 1980 in Minnesota. In 1985 I opened my own store by then I already converted all by BCs to Jackets w/ power inflators, and Alt Air sources for the regs.
If I would start teaching today, I would have BP/wing systems and long hose regs. I would also redesign the class to accommodate the equipment and the adjustment time for it. I know that they have glide systems on the BP's now but back then you had to manually thread the webbing through the plate to adjust them. That would take too much time just for one piece of equipment. If you are going to be teaching alone to start with, it would take a bit of time to get your student set up for gear if you go BP/wing and the cost will be a bit more. You are in a business now, don't bury yourself in debt before you start making money.