Hi, I also explored the options not so long ago. If you are wanting a "straight bolt in" replacement cartridge for the early strut set up, it seems nobody makes any these days ,up until about a year ago KYB made some but these were made for the later type strut top, it is what I did when I did mine up, but these are now discontinued as well.
For the rear KYB made a pair but I do not know if they are still available as I used adjustable GAZ shocks. (listed for Avengers) but these are not exactly a straight bolt in swap as the little hump in the boot needs to be cut off to clear the beefier top bush. Bilstein also do a rear shock but I do not know if the top needs to get the chop and they are expensive.
Apart from that its finding some new old stock which I see for sale from time to time or modify the strut to make something fit.