Aside from the interior being particularly ugly (it looks like they forgot to design it, threw a bit of plywood in there and then threw a bunch of switches at it!)..
The engines are renowned for being bullet proof - the bottom end is allegedly good for ~750hp without modification, and they were very popular for modifications in Japan so there's a whole hill of parts available for them from places like JapanParts, Nengun etc.
If they're anything like the 300ZX of the same era, look out for rust starting in hard to reach places - they have all the corrosion protection of wet paper towel once the paint is holed. Imports used to be better in this respect in that they hadn't been here as long - but by now they're probably getting in the same state as UK cars (i.e. either sheddy or good depending on how well they've been cared for).
Oh, watch out for imports - insurance will probably bend you over and stiff you purely because they're an import, and you'll lack any kind of service history before it hit UK shores (unless you get lucky and can read Japanese!)
You looking at the turbo model or the naturally aspirated? I imagine the NA engine is just about impossible to kill..