You can import any car so long as you can pay the taxes on it :P
It wouldn't be road legal, but you can do it
Please look at HT's A/C forum, a person has imported a S2000 VGS from Japan
Obviously not 25 years old.
*edit*
My point of posting that is your article has nothing to do with that specific skyline - you can "register" it if you follow
I believe public can view this :
http://www.accordinglydone.com/forum...ad.php?t=12588
worth the read

Chris no longer sells the Skylines listed there, but lists what it takes to make one registrable.
If you can't read that link
$75000 + 4 converted (US street legal versions) cars + crash tests/etc = registrable is the gist of it
You can bring over R32/R33/R34 but they wouldn't be legal to drive