Welcome aboard Thiink.
Where to start? I/we recommend the smallest aperture is an 8" Dob. It all depends on what you can afford, size of car, etc etc. The 1st rule is *APERTURE WINS*, but this comes at a cost. You will be happy with an 8"/10", until aperture fever hits. The main thing to do, is to get away from the %#^%&*%#@+(&#,, street lights etc . You must have a RED LED torch tho. & a planisphere is also helpful for finding your way around, and get a copy of ASTRONOMY 2005.
The others will point out more options. I'm not up with the GS Dobs.
I'm happy with my Meade 10".
ps. you mentioned the Bathurst Observatory. Why not ask if there is a local club/society and look at their t'scopes to get a better idea?