tom (tjv) sells a similar set up for the Big Green Egg at ceramicgrillstore.com called the Spider..
Not sure how many people cook with woks on Webers but it certainly could work or maybe start a new craze !!
22" WSM & Kettle
Former owner: Jambo, Klose BYC, Med. Spicewine, Pitts & Spitts, XL & (2) Med. BGE's, (2) 18" WSM's