Cruise Control Question

[deduncan]

Check this out:  http://www.mnrelectronics.com/par26cruisco.html

 

I have a base model, and would like to upgrade to have factory (if possible) cruise control.  I spoke to my local dealership, and he said it's a lot more involved than a simple computer reprogram.  He said that a wire or something would have to be installed from the throttle body to the gas pedal, or so he thought.  He mentioned that the duramax and the 8.1 versions have fly-by-wire cruise control, so this extra install wouldn't be necessary, but he wasn't positive whether or not the 4.8 liter version had that.

 

Has anyone gone through this process?  Any comments that can help me out?  He also mentioned that installing the escalade cluster would void my warranty.

 

Any input would be appreciated!