the stock 2jz supra makes stock 280hp not kw australian and japanese standard.. the american ones come out 320hp.
there is an lj torana down the gold coast with an rb20det in it.. that only just fits in that.. and also a lj gtr with a sr20det in it.. both are very quick cars.. the 2jz would be a good option but also consider these options as well.. it would be cheaper to put a nissan sr or rb20 in and would be still a very quick street car