The TEA "LASH" is a favorite with PD and SWAT. I believe they've been used by numerous SOF Forces as well.
They can be used with most two way radio sets. They do have the technology that your looking for for drowning out louder noise while maintaining clear comms with your team.
I own two sets of these and they are top grade. The throat or the recess pad must be used to transmit voice transmissions. The recess pad can be put on any part of your gear, but I'm not sure about a "custom" ear piece ? The are not wireless however. They have ear pieces for just about any ear size. Keying the recess pad is easy, even with large winter gloves.
HERE:
http://www.swatheadsets.com/tactical/Lash/web_lash.html