I am wondering if you are up to implementing some weird keysets like this one http://lirc.sourceforge.net/remotes/canon/RC-1_RC-5 for controlling DSLR cameras. They usually have a few buttons and I don't know how well they are going to fit in your layout. Of course there is pyCake but yet again it uses the LIRC daemon... If you don't think it would be appropriate to include them I'd give it a try and code a small app for it (probably ripping some of your code )