Thanks for all the feedback guys. The bikes I listed are all Australian models as I'm from Melbourne.

I just tried a Kona PhD in a shop near by which is on sale for $1300. Very nice bike to ride and quite aggressive riding position. It was a 56 cm frame (last one) and it felt just a tad too small. The guy in the store put it on a scale and it came in at 9.3 kg.

I then also rode a Trek 7.6 FX in 20" in another store and that felt more upright and comfortable and also better in size. The guy from the store actually suggested a lower spec 7.3 FX as a starting point that doesn't break the bank at $550. I'm going back there in couple of days to try it in a 20" size. The weight of the bike felt similar to the Kona so I don't think weight will play a big part in the decision.

Cheers,
Toni