How tight is your budget? have you looked at doing the body work and having a professional spray the car in a nice down draft booth and have the paint baked? I'll be spraying primer one panel at a time to prep the car. After working in the body shop industry I know that over spray get everywhere. Is this garage attached to your house? I'm trading off the costs of building something I'll maybe use once for someone else to take the risk of messing up lotsa $$$$$ in paint and your garage. Hotwheels Jr did this with really nice results.