in regards to the forms you'll have to contact the DPI
my mate in the Army when he was in Darwin wanted to buy my 180sx but it was too complicated for us but there was a bit more to it than just buying and selling
all the R34 GTT's that are automatic are tiptronic... there's quite a few members here with tiptronic ones so they'll be able to give you their opinions, i had a disagreement with some guy from Sydney as i personally think that a tiptronic one would not be as fun as a manual one, especially with our roads here and when you go on cruises and stuff there's plenty of roads that cater for fun/spirited driving
i know a lot of guys in Sydney and Melbourne however have tiptronics as their traffic is real stop/start so the automatic transmission comes in handy
if you're looking to modify and take your car to track days and 'enjoy' so to speak your car a little more i'd stick with a manual
a bit biased though, i hate driving automatics unless it's made to be automatic ie. a Lexus/Mercedes... couldn't imagine driving relative's cars in manual
less fun and puts you to sleep with late nights
my2c anyway, hope that helps