Hi, I am new to this forum too, I have a 2000 year manufacture Cygnus, ( Amazon from UAE ), I have been going through various tasks before a full underseal job.
One of those was to decide what to do with the AHC. I decided to keep it, and have currently replaced all four shocks with OEM units from Rough Trax, ( not cheap ). The pipes leading to the shocks have surface rust, and will be treated to minimise further corrosion. If they go in future, I will replace as necessary.
Here is where I buy parts from, often cheaper than UK Toyota dealers, unless excessive size . . .
Looking for genuine OEM Height Control (Auto-Leveler) for 1999 - 2002 Toyota LAND CRUISER UZJ100 (Japan sales region, , 17727310-910668)? Check on MegaZip at discounted price from manufacturers' warehouses in Japan, USA, UAE. Detailed diagrams & catalogues. Worldwide shipping. Easy to find parts...
www.megazip.net
I chose to keep original set up, as I read comments from people with fully functional systems, saying the original set up, for the road, is second to none. I also like to keep original if possible, I wasn't too keen on leaving old AHC components about the car after a delete. I'm sure many would not agree, but each to their own.
I believe that once you get on top of the corrosion issues with these 100's they are built in such a way that allows self maintenance, including the availability to obtain parts, ( so far !).
This forum is a great help with descriptions of tasks and experiences that help in keeping things affordable.
The previous owner of my LC was frightened to submission by Toyota main dealer in trying to repair AC system, but thanks to a thread on here, I was able to get system running, including a new Denso compressor and condenser for less than £1000.
Yesterday, I managed to remove the fuel filler pipe to replace, again with the assistance found on here in a thread by Bob Murphy
Of course, YouTube helps with some tasks and advice, you can then make an informed decision.
Hope this helps, good luck !