Thanks to everyone who responded to my inquire on UL and FCC certification.
Our system is already in production for quite a few years. So I believe
(according to your posts) it would be too expensive and time consuming to go
through certification process. But from other side it's not consumer system,
so may be its not going to create a problem (didn't before...)
Thank you again.

Gennady Palitsky
Jefferson Audio Video Systems
gennadyp@mainlink.net