I bought a Pro-q stacker off of eBay that fits well on my old Jumbo Joe, not sure if it fits on the new ones. It has to be inverted to fit but it works. Sorry, no link but you can just search on eBay.
Co-head cook of Smokin' Timbers BBQ
Sponsored by Big Green Egg, Oakridge BBQ, Sam's NW BBQ Co.
XL BGE, Two L BGEs, 22.5 SS Performer Blue, 22.5 Weber Kettles (Grey, Green, Brown, Red, Two Tone Red) 22.5 WSM, Three 18.5 WSMs, Mini WSM, Rib-o-lator, Green Thermapen, Stoker with wifi