Your thought that with your limited knowledge it would probably be easier to put a non turbo non fuel injected 13B into the car than a CA or SR is about right, but in NSW the 13B will be harder if not impossible to get registered.

Its always going to cost you a lot to do any legally registered high powered non A series conversion, but as previously stated you will learn an awful lot in the process, if you buy one already done and registered it will cost you less money than doing it yourself.