For the record, you may see some of these show up on ebay or something, they have been discontinued (really they just changed the line, same hardware with more variation and flexibility, which also means more variation in pricing, but also stuff like a transmitter/receiver option).
Since they are discontinued though, some companies may replace soon, so they may show up somewhere for much cheaper.
Neat project! I especially like that it goes for raw keycodes, real nice approach.
Unfortunately the Windows support is a hard requirement for me, but hopefully someone else sees and takes advantage