I used Unicar in Sparta for some body work
Can't help you on the price, but they paint all of the Mercedes referred to them by the Mercedes dealer in Newton NJ. They do a nice job.
As it relates to the trim. That 's what my dad did when he had is car repainted. It held the cost down and also prevented overspray. He said it took him a while, but what the heck, he's retired and has plenty of time.