Supercircuits has a huge selection of board cameras of all sizes. There are a couple "snake" cameras (very small front end with a tethered main board) that are good and small with pretty decent image quality. I believe they have some good 2.4G transmitters as well.
They are mail order. Shipping to Canada can get really pricey, don't know how it is to the states. Damn amazing selection though, and prices are decent.
Mark