Sounds like a great project to me. Have to start with the right vehicle to put the time & money into though. I'm thinking a bus that started life serving a retirement home or similar where they are not likely to beat it to death. Knock on the doors of such places. Ask if they are thinking of getting something new & might want to sell what they have. You never know. The worst they can say is NO.
I did that with a boat. A few months later the owner called. "Still want to buy it?"
Diesel would be nice too, even if it is swapped out for a remanned engine.
The rest is up to your imagination, time & skill.