My bus is in my back yard and I'm just passing year two on the conversion. Don't underestimate the challenges with having to travel to work on the bus. Think storage materials, noise, security, etc.
For your situation, you may need to budget significant dollars to do the work. And at that point, maybe look at partially converted rigs for the additional dollars you'll need to commit to the build process?
Hey hey! I'm starting my build in the Chicago suburbs, one thing I found is that some U-haul places have RV rental spots. The pricing is pretty reasonable and the ones I looked at had unlimited access during the daytime hours, and said they were ok with work being done at the yard. Hope this helps! Good luck with everything!