Note also that QF schedules can and do change, and some sectors can see aircraft types change - even a few weeks or days out (let alone on the day of flight for some reason or other) - this is specially common on the trunk routes MEL-SYD-BNE etc. I've "lost" a 332 booked flight several times to have it replaced by a 762 or whatever. Less likely on the longer hauls like CNS-PER, but you never know - it is still a few months out from when you want to fly, so don't rely 100% on what a/c is listed for a specific flight.
Best seating in J would be the 738, 767 or 330. Also note on the 330 the video screens are IN THE CENTRE SECTION ONLY (except for bulkheads), so if you want to watch the movie, you might want to keep that in mind. i found it difficult to view with ease from a window seat!