There was only a handful of S30z's and in particular 240z's to start with in Australia anyway. I'm surprised prices took this long to take off if I'm honest. I'd say you can still get what you want, but you have to look at importing from the US. Which has its own risks / rewards. Finding a car like you describe is very hard, I'd say you're better off building it, I know you say you don't want to spend hours working on it, but as Mick Jagger says "You can't always get what you want".
The 2+2 is also an option, cheaper and easier to find. I don't know why people overlook them to be honest. They look better than Z31s and Z32's in my opinion, not to mention being easier to maintain mechanically, cheaper to insure and cheaper on reg if going for Classic / Historic..
I wouldn't write off a 2+2 unless you have seen it in person. Photos don't always translate well.
Or what about an early RX-7? In my opinion still very under-valued.
Example:
http://bringatrailer.com/listing/1984-mazda-rx-7-gsl-se-2/
Although I'm more partial to the early ones (series 1) with the earlier style dashboard. 13B Turbo in them and they would be weapon!