You are going to have one fun project. I would do your google search on rv bus conversion. I did a quick one and there is alot of information on the projects.
I think your hardest part is going to be the plumbing, as the bus is a low floor. Once you figured that out the holding tanks, the water lines etc. the project should be easier.
As for driving a 40' rv or bus once you get used to it there really is no problem. Right hand turns do require some planning, as does stopping.
Have fun and good luck
Itasca Meridian SE 36g
Road Master Tow Dolly