Hi, Those are super-cool cars and they also had other factory options - in Japan- that we never got in the USA.
You'll want to search online for the 'valley of death' (turbo reference), and this site has some info: https://en.wikipedia.org/wiki/Subaru_Legacy_(second_generation)
The engine should be similar to any other EJ20G/K/R series engine: https://en.wikipedia.org/wiki/Subaru_EJ_engine#EJ20
These should be Phase 1 versions, until about '98/'99 for the JDM versions. Japan usually got the next generation a year before the USA.
The turbos are unique, AFAIK, to the twin-turbo models. So if they fail, it'll be a challenge finding a replacement. I've read that they can be converted to a more 'normal' single turbo setup, but that'll take some Googlin'. They'll also likely have a unique top mount intercooler setup. If the hoses/fittings/etc. fail they can be hard to find.
I've had some success using ebay's UK site: https://www.ebay.co.uk/ Check with the SELLER before buying anything to see if they'll 'post' (ship) to the US.
Also, there is a member on the Legacy Central site that may be useful for info, see here: http://legacycentral.org/ Joshua Colombo (Legacy777) knows the guy, too. Josh used to post on here but he's the Admin on Legacy Central. I think his name is Michael Block: https://shoutengine.com/CrankJournal/reengineering-with-joshua-colombo-40015
And there may be other online forums based in Australia for info...since they're also RH drive I think they got these.
GL,
Td