Joel,
Check out Bintel in Sydney for a good range of Dobs. I have the 12" SW collapsible scope on a dob mount. It makes transportation quite easy. The scope and mount fit nicely into my little Hyundai. The 8" is a great starter to intermediate scope and will give you fantastic views compared to the 4" refractor. Bear in mind that a dob mount is not suitable for astrophotograhpy, so if that's not your ambition, go for it. If you can afford it, go for a "goto" model, it makes life so such much easier.
Clear skies
Rod
