This is a fantastic idea! I am a yacht captain and spend a lot of time in the Exuma's with my boss. I can't tell you how many times I've wished I had access to a Hobie 16 down there! I would be all about renting a Hobie from you if you were to buy a number of boats. Below are a few thoughts on the subject.
1. Definitely the Exuma's and not the Abaco's. Exuma's are MUCH prettier and more to see and do.
2. I think it should be done with Hobie 16's. All that wind and flat water would be a Hobie 16 paradise.
3. I personally don't think there is any need to go further than Staniel Cay. There is so much to see and do and places to visit between Alan's Cays and Staniel Cay, it's just not necessary to go all the way to George Town.
There are several good places to make stops at night, and I'm very confident you would receive a lot of support from the owners of the various marina's, hotels, and resorts.
Let me know if I can help you with anything...
I hope this works out!