Do a Google search for "Multiplex USA" and you will find a number of matches that should help.

Some of the RCU members are also MPX dealers who may be able to help you out, but because of the recent clampdown on commercial posting, they aren't actually allowed to make posts in this forum, in which they offer to sell you product. Maybe they can contact you "back channel" with the info you need.

You may also want to contact RCU user "woketman" - he is a Multiplex rep, and can help you out with any questions you have.

Regards,
Gordon