There used to be companies like Fridgette and ARA that made aftermarket cruise systems for non-OEM cars that installed very easily, had their own control systems. Many moons ago I worked at a company installing these. The option of an OEM style stalk controller or a dash mounted box were available. Not sure if they still exist or if they have been replaced by more solid state type of units.

I bet some one at Car Toys could answer that question.