i got a suggestion (Score 1)

I actually have worked on something like this for the company I work for. We wanted to use remotes to control LED signs, and were tired of the RF remotes, bought off the shelf, we were using because of their short rage. Instead we develped our own remotes using the ZigBee protocol. The chips that we used were the XBee chips from Maxstream, along with a pic chip. The range on these are amazing, getting 4000+ feet using the pro module. It is a small enough chip you could fit on a small PCB board and fit in a small remote unit. As for the addressing, when programming the pic chips on the remotes, use the chip burning software to serialize each of the chips. you could then access this data and send it in a packet along w/ the button u pressed. This could all be sent to a "master" box that has an xbee module and decode all of the data.