I'm a fellow Aussie VV user. I haven't come accross anyone doing a turnkey system here but then again I don't see much need to go down that path as VV is pretty well hardware independant.
I just put a half decent system together from parts I purchased myself and installed VV. Apart from making the mistake of thinking PATA RAID 0 was a good move and ending up dumping it, I've no problems with my hardware running VV.

I don't know, if you really don't feel comfortable rolling your own, New Magic might be able to do it for you. I'd suggest avoiding Dell unless you know what you're genuinely getting. I've heard they don't use industry standard parts so if a bit does go belly up you've got to buy their bits. The way I've put my system together just about anybodies bit X will will work with the rest of it.

I do build PCs myself from time to time, only usually for mates as there's no money in it but... Then again you could checkout AusPC Market, never had a dud bit from them or else Computer World. I've never bought a system from either of them so I don't really know how well they go putting all the bits together but the parts they sell seem to go together no problems.