I don’t have the Genesis but this may help. The Rotisserie Kit you speak of is the 9891 which does look quite complex. Have you looked at the 9890?
The 9890: Rotisserie Kit for the Weber Genesis 1000, 1500, 2000, 3000, 3500, 4000, 5000, 5500, and Silver C series barbecues. Contains spit rod, 2 spit forks, motor mount bracket, electric motor, and rotisserie counter balance. Here are a couple of links. The second one had a photo.
1. http://www.mainstreetfuels.com/weber/we ... /wsilc.htm
2. http://hallkids.com/index.php/Mode/prod ... 331/page/1
Attaches to Weber Gas Barbecues. Includes a heavy-duty electric motor, on/off switch, wood rod handle, and counterbalance for smooth turning and less motor wear. Item # 141759
3. http://www.bbqgalore-online.com/BBQ2001 ... rparts.asp
Good luck. Hope this helps.