The horses mouth
GAM stands for General Aviation Maintenance
It is based in Essendon Melbourne and conducts primarily freight operations from all bases except Cairns which is mainly charter work conducted through its subsidary Reefwatch Air tours.
I think, and its only my opinion that 1600hrs instructing is enough, and some charter would be of essential use to you at this stage in your career. There are some things you can do before up and leaving however, make the calls to the people your interested in and get a feel for the place. Another thing you have going for you is that you work in bankstown, GAM operates 2-3 aircraft from that port !!!!! So find out where the mayne nickless terminal is wait for the AC-690 to turn up late in the afternoon and when the pilots has a chance introduce yourself to the senior base pilot. Best of luck in your endeavours.............................