I am currently working with a national chain auto repair center and they have been very willing to allow me to bring in my own SS brake lines and A/C parts. They did take me to side and ask that I not discuss it in front of other customers because they are not suppose to use any part other than what they can obtain. They kinda opened the door when they couldn't get pre-bent brake lines for my '93 and I found them on the net.
Thrust me they make money on parts.