Retrofitting cruise control into a jeep cherokee XJ 1999?

Not sure what the kit cost but I helped a friend fit an aftermarket kit to a Renault Espace.

It took depression from the intake manifold to control the throttle quadrant via a diaphragm chamber.

Then there was the on/set/rest switch and control box which is the easy part once the switch has been located sensibly.

This was a kit available for just about any car / van.

Had a cruise control aftermarket system in a Nissan D-22 2.5L TDI. It was mechanical and used a cable to open the intake manifold. It had a sensor to disconnect when touching the clutch or brake. It would also disconnect if the engine was forced, like going on 5th gear on a steep climb, altough I don't think this was feature of the thingy I did like it.

The price for the installation should be around US$250 in my opinion, you don't wan't to go cheap here. The kit I don't really know, because we pay "My country" prices around here but on ebay the one I had THIS CRUISE CONTROL is on the US$200 price point.