Looking to get some Lavalier for the work we do with theater performances and wanted to get some input.
We would be using the them with our Shure SLX kits.
I've been looking at countryman but can't decide on the b3 or b6 also trying to figure out which sensitivity I should get. I'm also open to other brands as well.
I think the B6 is a very good microphone; the B3 has been the "budget" standard when "Sennheiser Mickey II/mickey gold/etc" were considered too spendy. If you're doing musical theatre get the least-sensitive models for 100% of your needs, and another 20% of the middle sensitivity to keep for actors with small voices. A singer with a big voice can overload the middle sensitivity and certainly would overload the most sensitive. A call to Countryman will be informative and helpful, they're great folks.
The Microphone Madness elements are "very good for the money." With the price point you adjust your expectations a bit and come away pleased with the balance of budget and tonal quality. A phone call to their office is also informative; they offer a couple of variations and modifications that are not on their website. I suggest getting a couple to try out, if you don't like them you can probably find willing buyers...
DPA is the 'big boy' standard of miniature mics, but you need a big boy budget. Very nice mics, though.