Wow and I thought I had a high tech wheelchair. If only all DME's showed the commitment to their clients that you've shown to yours. Bravo to you sir!
The chair I'm currently using is an Invacare TDX5 with power tilt/recline, shear and legs. The drive system on this chair is the NewAbilities UCS1000 Tongue Touch Keypad (TTK) System. With nothing more than the tip of my tongue I can drive the chair, adjust the seating, make a phone call, operate my TV, computer/mouse, lights, automatic doors, thermostat and more. Unfortunately the company that makes this is now out of business so I'm going to have to switch to something else and you've show me some pretty good ideas.