Specifically I'm looking for eight wireless face mics that would be good for use in a musical. I'm located near Philadelphia if that helps.
your best best for that may be to look for A/V rental companies. by that, i mean the companies that supply projectors and sound equipment for conferences and the like. you'll probably have better luck with them than the usual production equipment houses; at least for the type of gear that you're looking for.
call up the event managers for some of the larger hotels or conference centers in the area. they always have a list of companies that they got to for that sort of thing, and they'll know which ones are knowledgeable and reliable. it will get you pointed in the right direction.