Ask to see some of their work, make sure there painters are certified, do they warantee their work, ask them if they intend to blend your paint into the fenders since its a metallic and you want it to look right. Call your insurance company and ask who they would recommend for quality not cost. Basically any reputable shop should be answer what I have just told you.
If they are painting in a wood shed, they may do good work, but they are not likely to be reputable.