A Carcoon (airbag) would be a good idea, as long as it doesn't get damaged during the works, sparks etc.
I bought the aerosole etch for my own project, as i work on it when i have the time, so at least i could paint the small areas of bare metal as i go. If there are any large areas of bare metal, i will mix some 2 pack etch, and use my spray gun, it's not economical/practical to use the gun for small amounts. Ask the body shop who you want to apply the 2 pack top coat, i'm sure they will have a preference.