I had a similar symptom with my 2001 LX very bouncy ride. I won't go into all the details, you can see my thread if you're interested. But my globes (front ones at least) were shot. There was some debate about what the cause of my bouncy ride was but in the end, with the very generous help of PADDO, I was able to pull my front globes and verify they were toast. Even if the back ones weren't toast, they were soon to follow. And keep in mind, my LX went to H & L OK. But my front end would randomly lower and then raise back up. Not normal. And my ride was crap (bouncy). Borderline unsafe.
I debated whether to bite the bullet and buy new globes but in the end, with the age of my truck, I decided to just go with the LC set up. I paid cash for the truck, bought from original owners. I put $1500 in maintence in it and hadn't planned on paying another $2k to replace the globes.
I was going to buy the LC suspension conversion kit from cruiserparts.net but I ended up having my mechanic buy the OEM parts from his buddies at Toyota (he used to work there) and I saved myself a little cash. The shocks are cheap, the rear springs are pretty expensive. But I paid him $400 in labor, $550ish for parts and another $90 for the alignment (done at a different shop down the way).
Now PADDO and others on here have said that new torsion bars need to be purchased as the LX bars cannot support the front end without the ACH system. I told my mechanic this and he said no, they will be fine. I quoted everyone I had talked to saying the opposite but he said don't worry about it. OEM Landcruiser torsion bars are not cheap, $300-$400 for each side and I hadn't really worked those into the equation. When I went to pick it up, it was perfect. He said the alignment shop had to re-index the bars but they were just fine. The height was perfect too (originally my front end was several inches lower than the rear) and now the front was about 1/2" lower...totally changed the look of the car.
How is the ride?? SO SOLID. I feel like I'm driving a nimble beast. It's completely stable and balanced. I've got a slight inclined portion of road on my drive home from work that goes over several rail road tracks. I used to slow way down and cringe as my front end bounced like a pogo stick. Now I can take those same tracks at 50mph and it's so tight. Is it buttery smooth? No but my other car is an LS460 so if I want a cloud like ride I drive that. With the LC set up, I can feel the road and I feel very secure. It's comfortable, and did I say SOLID? I don't know what the LX should have rode like with a proper functioning AHC system because mine never functioned properly. But I'm so glad I went with the LC set up. It should be headache free.
My mechanic that did the work also drives an LX470, his is a 2006. He compared the LC ride to his and said it's somewhere between the middle 2 settings. Not COMFORT and not SPORT. I'd say that seems somewhat accurate but again, my ACH was tainted. Side note: He said as he emptied out the ACH reservoir, there was about 1/2 of sludge at the bottom and he's almost certain it was power steering fluid. But the system was definitely contaminated and after hearing that, I was so glad I decided to move on from the ACH system. Whatever the sludge was was most likely in the lines and everywhere else in the system. Not even sure if you can clean something like that completely out??
And he disconnected the ACH system under the dash so the ACH lights on my dash are out and I pulled the ACH control on the console and put in an OEM LC console dish. So it looks pretty stock.
That's my story, hope it helps.