The Nissan Path

I need some help. I know this has probably been discussed to death, but I can't find anyone who states they have resolved the issue. I bought an 06 Pathfinder with 43K miles on it (at 114k now). The rear bounces like mad when I go over any bumps more than a couple of inches tall. We're talking the rear feels like it's coming off the ground. It keeps bouncing five or six times before settling down. I nearly lost control a couple of times. For example, when I go over a bridge where the pavement climbs up a little it's like an explosion lifts the rear. I've replaced the springs with OEM springs. I've replaced the shocks and struts with Rancho 9000s set at 9 and added the Airlift 1000s. I've replaced all the sway bar links and bushings. It really didn't make any difference in the rear. The front is very firm though. The rear shocks have failed twice on the right side (blew a seal and the adjustment knob wouldn't move,) and once on the left ( the upper bushing was split). Does anyone have any suggestions on how I can stop this? Would changing over to Bilsteins make any difference? It just seems the shocks don't have enough dampening strength to stop it.

I've got the Bilstein HD rear shocks with Airlift 1000's (set to 15 psi) on the back end of my 06 LE 4x4 and have been pretty happy with the ride. It's still stiff and a bit "unsettled" on bumpy roads, but to be expected with a body on frame SUV with an independent rear suspension. Having the alignment in spec and choice of tires make a big difference. Currently, I have Nitto Dura Grapplers on it and they ride like a truck tire. I was much happier with the Michelin LTX M/S2s that were on it previously, but they are pricey.