Electric bike kit with cruise control

It seems like there are some production ebikes which have a crusie control feature to maintain a desired speed.

I haven't heard of any ebike kits with this feature though. Maybe someone else here knows of a kit with cruise control?

(Based on your username, I'm assuming you need this feature to get to the nearest bathroom on time ;))
On my "Ebike Kit" the S830 Controller cruise control function is activated with a long press of the down arrow key when traveling:
"When the vehicle is traveling, long press to enter real-time cruise mode. or engage the Throttle to exit the cruise mode."
Old thread, so just for the future reference of anyone asking the same.
All genuine KT controllers and displays have a 'cruise function'. So just make up your own 'kit' built around this central items.