Darrin
Best you do some searching and reading on this site. Look through the Projects & Articles and the Equipment Reviews sections up there to the left. There are articles and reviews that talk about improving the movement of the standard Chinese dobsonian base. Then search the threads. From sometime in early 2007 you'll find a thread from me on improving an 8" Bintel dob base. Search "milkbottle washers" to find a way to add some washers to support the pivot point.
However, I'm not sure what the new crop of Chinese dobsionian bases come with these days - they may have incorporated some of the better and cheaper ideas. Some incorporated a ball bearing lazy susan into the base. Some love them, other say they don't provide enough friction and your scope turns into a windmill if the wind comes up!
Best to find your local specialist - you have Sirius Optics in Brisbane, not sure who else - help me banana-benders! Then you can have a good look and what is on display. Sirius sell Skywatcher. From what I have seen, these sell at a premium of some 30% over other brands - say GSO. They get good reviews. My understanding is that most of these solid tube dobsonian-mounted reflectors come from a couple of Chinese factories. For example, I understand that the ones labelled "Bintel" are GSO telescopes, locally checked and labelled. I've had two Bintels now - an 8" and a 12". I'm happy with both. I cannot see why I'd pay a significant premium? However, others seem happy to do so. Andrews Communications in Sydney are worth a look if you really are tight on $s. They often price under most others.
If you do find that you want to buy from Sydney, consider cost of shipping and possible damage through shipping. We've had some bad stories lately around shipping.
Telescope accessories. Well, I believe in a laser collimator. The GSO delux would be fine. Others will say spend your money on an Orion combined sight tube/Cheshire collimator instead. Search out some of the collimation threads in the last six months to read the arguments for and against. However you do need a collimation tool. If you buy locally, you should be able to get the store to demonstrate how to use it on one of the floor models.
Apart from that, a red light torch (but you can make your own with red cellophane). Eveready do a head mounted torch with red light and white light - supermarkets/Kmart etc. for around $35. Do you have what you need to find your way around the sky? If not, then one of the large Planispheres. Download Stellarium (free) to your computer and use that as well. You may find it comfortable to sit down observing - there are special adjustable chairs (expensive) - I just use an old office gaslift chair with the back pulled off it. (Can get bogged in soft ground
) Don't worry about coloured filters. The filters you really need can wait a while - they won't be cheap.
If a barlow lens doesn't come with the package, pick up one of those. I'd recommend the 2" 2x GSO ED barlow. It does various things - mainly magnify by two times. Adding that to your eyepiece collection gives you a wider range of magnification.
Cheers
Eric