Head units that have triggerable outputs...more...?

Not sure if anyone makes this type of head unit or not but have an idea for one of the car's Im working on.....

I'm adding heated seats to the car and there will be settings of "off", "low" and "high" for each seat using 3 way rocker switches. Are there any touchscreen head units that have voltage driven outputs (similar to remote turn-ons) that can trigger the various states of the seats? and secondly to control this operation- the unit's ability to have buttons programmed to control my seats? I thought it'd be neat to not have to install the controls for the seat heaters in the center consul or where ever and just have the seat controls integrated into the unit's functions.

Am very fluent in home theatre and have done voltage triggered operations (drapes, HVAC, lights & etc) commanded via pc programmable touch screen remotes (pronto / URC). So, I'm kind of looking for the same result here but not sure which manufactures have this option in the car world.

Any help is appreciated!
-john