Very interesting sir. How about the price range of the vocal wireless systems?
for wireless vocal mics and Lapels, you won't go wrong with
MIPRO.
its fairly prices, durable and accepted in most if not all situations, even in the networks.
did you know that MIPRO developed & patented the Frequency AutoScan & Automatic Channel Targeting concept
way back in 2001 which is now, in the past 4 years or so, a staple feature in some models of SHURE, AKG and Sennheiser?
as long as you maximize these functions, you can use multiple MIPRO units, up to more than 40 sets, in 1 area, without any problems.