Im replacing the lower door molding on my driver side door. Does the body shop
 

order the paint to do it or do I order everything and bring it to them? If I do, where do i order the paint? Im going to purchase the molding from ECS.

any good body shop should be able to order paint/mix based on paint color. You could also try..
 

paintscratch.com and DIY, for something so minor low to the ground. Just make certain alot of flex agent is used.

the body shop will get the paint

www.paintscratch.com, or have a good shop match specifically to your car in person