I'm no expert, just another searcher for the perfect telescope. A
couple of things I've been grappling with though:

Also, in you opinion, should I go the extra NZ$300 and get a 10" rather than
an 8"? Here is a link to the 10" (http://www.astronomy.co.nz/pub/GS880.asp)

Check out the size and weight of that 10". If you plan on moving it
much and are going to be setting it up yourself, that is really
something to consider. I'd love a 10 inch, but the size is just out
of my league at the moment.

As for the mounts, I'm shying away from the Dobs only because of the
lack of drive motors. The only drives I've seen for a Dob are very
expensive indeed. I'll admit that I'm a bit lazy, but I want an
object in the viewfinder to stay there without me making constant
adjustments.

Let me know what you decide on. I don't think my budget is too
different from yours and my astronomical experience is different only
in that I've been using 10x50 binoculars.