I've been to Coz only once - I'll be back, though. I dove with Aldora and had a fantastic experience, and they certainly meet your dive op criteria. I obviously can't comment on other ops, but I went through the same research on scubaboard that you're doing, and even though I chose to dive with Aldora (and will dive with them again), I suspect I'd have been happy with a number of ops that you've already identified. I will look forward to trying to get out north with Aldora next time.
As for accommodations - I found a place on AirBnB. I like to stay in an apartment or condo for the same or cheaper (which is usually the case) versus a resort or hotel if possible. I stayed in a private cottage just far enough outside of the center of town to avoid loud late nights when I didn't want any part of it, and just close enough to take a short walk and join in on the shenanigans when I did want a part of it. If you're not committed to a resort or hotel, you might look at options to rent a private place.
I've had the good fortune to get to dive a wide variety of popular vacation diving destinations around the world, and was really impressed with Cozumel. I expect and hope you'll have a great time regardless of which dive op you choose (among those you're considering) and where you stay!