U should be ok with the garage, wouldnt start with 200, go with 180-320 to get the chips out, Then you Primer using a 2k primer, then when the primer dries, sand with 400-600, then you apply the basecoat, then the clear coat, woldnt waste ur time with the hot air thing, i've heard it messes with the hardener and messes up the solvents, and affects the normal curing abilities, But i would get a few test panels, say a hood or something, and actually practice a bit to see how things work out. That and buy good materials! No nason or NAPA paint!