Im with Scott and Dave. This is the kind of work I do every day. Its a crap shoot, as to the time it will take. Just like a car, its all about the condition its in. To clean, polish, and protect it, you could be into a 40 footer around 40-50+ hours. Those are the projects you'll wish you had employees for.
KAIO is a pretty good one-step for full paint coaches, I've found.