$1k for the rears alone!!!! F*ck me!!!
Depends what you want.
If you need them to be height adjustible, look at Bilsteins or by all means go through the M35 Aftermarket Suspension thread and make your choice, than email RHD to get it listed and buy through them (you usually get a 5% discount if you buy the item you get them to list).
If you don't need height adjustment, go with the Nismo's.
RHDJapan has them listed new and will ship to NZ, just create an account.
RHDJapan is HIGHLY recommended for all new stuff