Welcome!!
Rare car the ix!! Apparently the 5 series was also released in ix form and the E class Merc (at least in Europe). Those lucky devils also got the 6 speed 7 series V12
Anyways, I have been seeking an SVX for a very very long time and also in a market where there are very few SVX's to begin with.
My advice would be to either a) hold out for a later model (and they come up very regular in US....cf Australia where there are 3 1997's!) or b) buy an earlier model but work into the price the usual things that fail - tranny, air con climate control (has become more common here..and also Japan as I understand it), drivers switches, bearings, leakage in rear lights, drivers visor..etc etc.
Also, I have been told that the driver shaft where it couples to the rear diff had a TSB - perhaps make sure that that was done.
Good hunting!!
James