Most shops don't use any kit. They use the flush and then install new service valves and a new drier. Then they vacuum the system down and install the new oil. The flush and oil and valves should be available at any parts store. I recommend the BG Frigi oil. It has worked well for me.
ASE CERTIFIED MASTER AUTO TECHNICIAN
LEAD TECHNICIAN FOR 14 BAY FACILITY
MERCEDES SPECIALIST 8 YRS
PARTNER IN MERCEDESSHOP.COM