Hi Matt
I am not an imager, but I can help with some of your queries. I have no hesitation in recommending Bintel (
www.bintel.com.au )for service and advice. Thay have stores in both Sydney and Melb and are knowledgeable and used to answering queries. I have also dealt with Andrews (
www.andrewscom.com.au ) with no problems, but have not had to ask any technical questions so cannot comment on their knowledge.
For imaging, getting a good EQ mount is the most important thing. From what I understand a Skywatcher NEQ6 is pretty much the most basic decent mount out there and it will use about $1800 of your budget. The cheaper HEQ5 is capable but cannot handle the loads.
Malcolm