Welcome aboard, fellow newbie!
I'm down in Southern Maryland. I found my bus not too far away (New Jersey, actually). A little rust doesn't scare me -- I'm used to seeing far worse on the trucks I drive for work ...
I've seen those busses you are probably looking at down in Southern VA -- I even talked to that dealer. The dealer seemed pretty straight up and honest and the busses looked pretty good. I just thought they were over priced. I was also looking for something unique (pre emissions AmTran with forward located wheelchair lift), so when I found one that met most of my requirements, I got it and am happy with it (one road trip under my belt now). It has a little rust but nothing I can't deal with here and there with a wire brush, some ospho or POR-15 ;)
Another thing to consider is the advice given on this site to not rip the bus apart as soon as you get it home. I followed that advice. I removed all the seats, and I removed all the school bus safety bits (flashing lights, stop signs, whip, etc) and repainted the bus to get the MD RV registration, but I'm leaving the bus open for now to get an idea of how I want to fit it out eventually. I built a platform to fit a double mattress and I use a folding table and some chairs for now. For curtains, I have a bunch of magnets and bed sheets.
Its a big metal tent! For me, it works great.
But my situation is different -- we'll probably keep an open floor plan because my wife is a t4/5 (complete) paraplegic and most fit outs I see are not wheelchair friendly
Which is why we went this route instead of just getting a Class A RV.
Good luck with your search and congrats on the retirement!