I see it!
(And thanks family bus for the tutorial- I've been trying to figure out that multi quote thing too- but how do you choose the quotes? I check the box, but can't seem to click anything to attach it?
Otter- That is a lot of animals, and you've got some that are quite temperature intolerant too... Hmmm... where are you located, and where do you plan to be when the weather is below tolerable for your birds, iguana and spider? They will require special consideration in your heating/cooling plans if too far north. I'm not trying to be discouraging, but rather help you plan for contingencies.... Lol
All in all, it looks like the guys have thrown out some great advice. I especially like the get a glamper idea (glamorous camping ICYDN) or just camping in a steel tent, especially if you are already campers. That _could_ be a good segue into a full-time conversion/conversation. Since space is a concern, I would definately keep your eyes on the 40 footers.
Even if you just strip out your starter bus and use it to haul camping gear and the fur babies, it would also give him time to get acclimated to the space too, especially if you will be abe to park it in your own yard (is your yard big/tall enough and does zoning allow it?)
One thing though- remember that the majority of school buses were built for lots of stop and go driving at low speeds. The "power package" (engine+transmission etc) of many of these buses was not designed for highway speeds, and some top-out as low as 45mph, and/or don't have the oomph for climbing hills. It all depends on who ordered what and their budget limitations. Some states also have higher minimum requirements. Activity buses usually do have better power-packages when it comes to highway speeds. Learn about this, and by all means don't get one of the 50 mph buses for your starter-bus unless hubby always drives slow on country roads! lol I imagine this would be a deal-breaker for most.
That cost-comparison of a house/skoolie idea is great too.
Someone once mentioned that they were able to live for about 1/3 the cost of their 'other life', so they split the extra left over cash - half went to bus conversion, and half went into a bus-savings account. Kind-of like a health savings plan. It was destined for the bus, but was for major infrequent expenses/maintenance/repairs like tires, tows, engine and tranny stuff- a rainy day bus fund.
Good luck with both of your conversions!