Zoltan
An 8" dob is a great first choice. As regards the models you have mentioned, optically there would be little to choose. Mechanically, from what I have seen the Skywatchers are a little better than the Bintel/GSO model, but the difference is smaller than it used to be. One small point is that the Skywatcher eyepiece adaptors always seem to cause issue for beginners, not anything wrong with them, just a different way of dealing with the issue of different size eyepiece barrells.
I can recommend Bintel as a dealer also.
I see you are in Kinglake. If interested in dark skies, the Snake Valley Astro camp is coming up soon (see
http://www.iceinspace.com.au/forum/s...d.php?t=137600 ) I am one of the organisers and it would be a great way to try out the scope in company and have a look at other gear. Let me know if interested!!
Cheers
Malcolm