You should be able to do about whatever you want with BVC (Bill's Voice Commander). It works very well with my X10 set up. I think a lot of the members here have it, and have good things to say about it.
I don't use a headset, but I have a wireless belt clip transmitter with a lapel mic from Nady systems($49, Dak.com), that works great.
I don't wear it, it just sits on the table or somewhere I'm at, and I communicate with the computer that way. 3 in-wall speakers, liv rm, Basement,, and garage, let me hear BVC reply back.