Get a DE, and upgrade to a DET later. The de-turboed DET will be mega boring to drive, and you'll be thrashing it all over the place to keep your hormone levels high enough that you don't go all emo (like most young people). This is the sort of time when the cops will bust you.

The way cops target hoons these days, you'll probably be on your P's for the next 10 years anyway.

DET to DE isn't a terrible idea, but the cost of getting headers etc makes it not really worth the cost. You'd have to get it engineered as a DET when the time comes anyway.

After reading the license restrictions.. If you live in NSW ..no engine modifications allowed. Start preparing to be "barina'ed"