Air Tight or Music Reference?

I am considering buying a new (used) tube amp for my system which consists of

Joule Electra L-100 MK-III preamp
Merlin VSM speakers
Audiomeca + Audio Logic CDP/DAC
JPS cables

I am very interested in the Air Tight ATM-1 or the Music Reference RM 200. No dealer in my area has either of those lines, but I found both of them on the second-hand market for a good price. Naybody have any experience with either? Any thoughts or suggestions would be appreciated.

Thanks, Dr V.