$22K is very doable for a 34, just don't expect to find anything but auto's for that price... but the Aussie dollar is getting stronger against the Yen, and the 34 is getting on these days, therefore they get cheaper with time... so anything is possible
As for mileage, most car yards consider 10-20K a year to be 'average', so an 8 year old with 93K is quite good/under average km, but condition of car is always the best indication anyway.
All the import companies listed above by R33-GTS are well established and reputable, with my own 32 GTR being imported thru Imports 101, who outlined the whole process for me so I wasn't in the dark.
Good luck,