i dont no what turbo will be good 4 my eng

how about a t25 or similar, also the toyota c12 are ok on smaller engines too, as long as boost is kept below 12psi (more like 10psi max) due to ceramic turbine etc

ok were can i by one in Melbourne

t25g of an SR20 would be ideal the CT12 is a bit too small I had a Toyota Corsa with a CT12 and is way way too small, I would have put in a T25G or a T28 so yeah there ya go,,,,,,,,,,ring all the jap imort part wreckers in the Yellow Pages

or try ebay, also you could try any turbo shop such as atp or similar, there are always bargains to be had on old turbos off cordia's and starions and similar as everyone ones an upgrade solution now days.
depends if you want a chaep alternative or buy a s15 t28 for $1500 or $2000.

all of the previous-mentioned turbo's are good (except for the CT12 - only good for a 1.0L engine) but there's one you haven't considered.

the CT9 off the 1.3L turbo Toyota Starlet import. Grant at Per4Manz Turbos in Welshpool WA sells them brand new for $495. perfectly sized for an A12.

if you have an A14/5 though, look towards the post 97 WRX turbo. these babies work wonders.

Ring Nissan, I believe the S15 roller bearing item is more like $1200 new