annsatar, you would do better to ask this question in the forum:
UL (underwriter laboratories) Code Issues
However, I believe that you will need to obtain UL recognition on the complete assembly (probably UL2200 applies). It certainly makes the task easier if components are already UL rated, but the final product will need to be inspected and tested by UL or UL approved agencies. This can be quite expensive; also be warned that changes to the equipment are not so simple, UL will want to look at the implications of any changes.