I'm 220#, and don't bottom, even with my wife on the back. So, let me ask you a dumb question, have you tried adjusting the preload adjustment on your rear shocks to position 4 or 5 vs 1 which is the way they come from the factory?
I second and third the suggestions for the Progressives is you want to replace the stock shocks. The 440s give a better ride, though I don't think there's much difference than stock in their ability to prevent bottoming as that is a function of the spring, not the shock.
2003 Dyna Wide-Glide' SE203 Cam, Mikuni HSR42 Carb, SE AC, SE-II Slipons, S&S Intelligent Spark Ignition, Race Tech Gold Valve Emulators / Springs, HB125 Tensioner, Passing Lamps, Mustang Touring Solo, Passing lamps
2013 FLTRU Road Glide - Gutless Cat and MadStad windshield
2012 Triumph Tiger800XC, too many farkles to list.