RE: 2000 Wrangler Sport and Invisibrake
Yes, I have completed the Roadmaster Invisibrake in my 2000 Wrangler Sport. You are correct, the installation is pretty straight forward. The biggest challenge was locating / mounting the cable pulley to the firewall. It all worked out, but added a couple extra holes in the firewall that I sealed with silicone.
There was not enough room to put the control box under the driver-side seat. I put it on the floor, just behind the driver-side seat.
As you most likely know, the Invisibrake is a "Progressive" supplemental braking system. I am installing the Roadmaster Combo Kit 9243-1 and the Roadmaster Falcon 2 All Terrain Tow Bar.
I hope this helps.