Would you be opposed to mixing in some flat to your rocker profile? If you would be open to that, most of the K2 line and quite a few Capita boards open up as potential options.
Boards like the K2 Raygun and Hit machine come to mind for stiffer rocker boards. The Ride Machete would be a little different profile than the WWW but I think it will fit the bill. I've ridden the NS Evo and the Rome Hammerhead and I loved them both for flatland tricks and general buffoonery, those are just as soft as the WWW. But if you're looking for more pop and a bit more stability those are two good candidates for sure.