Yes, you could get your wires from Fastlane. I've been buying parts from Caliper Motors for a long time and the service has been excellent. Prices are 25% off list. They are an MB dealership and they seem to stock everything or can get the part in a day.
If you are near to California, call Al Trevino in Parts at 1-800-252-8877. The MB Club members used to recommend them and they advertise in the Star.
I live in Arizona and get parts via UPS ground in a couple of days.