All Marzocchi's will do the trick, there are lot's on the market. Rock solid. Full seals support(!).
Also a lot of parts are available. Easy to service, most of documents can be found online, cool community (FB is most active).
Check my Marzocchi Manuals Repository : https://public-repository.org/
Scan it and make it public. It is a pleasure to host those documents for such wel known brands.
If anyone have some more than here please post it. I make them public available in my repository for free download.
https://kona.public-repository.org
You might want to buy directly as usualy it is cheaper as Ebay because of fee's and I do RetroBike discounts.
There are 3 different Seal Kits for XC500 from small to complete (including sticker, tools, 2! sets of seals, bits etc.).
Happy to answer your questions about!🤙
Check my Marzocchi...
Yes, Marzocchi did 2 rebound cartridges with the orange Z1 and others and started doing compression cartridges ~2000 - afaik. They can be identicated by the black anodized needle screw in the center of the cartridge and are backwards update compatible. I have some here 100mm travel.