There's one called the Blue Ant that the outside sales reps at my work have and they really like it. I believe the cost is $100 or so. I just went and got a new headunit with bluetooth which works awesome with the mic on the a-pillar. If you need a new deck go that route but the Blue Ant works great.
Heres the one I was talking about. I'm sure you can get it cheaper then that tho.
http://www.bestbuy.ca/en-CA/product/...5c4884ec5een02