Yep! They certainly are legal to drive on your P Plates. They're not over the power threshold, not V8, and not turbo or supercharged. They're practically the perfect sportscar to have on your P Plates.
I'm not sure whether you're on your P1 or P2 licence, but the pages are pretty much the same:
http://www.rta.nsw.gov.au/licensing/gettingalicence/200707_p1.html