I just received an email from Hubble Optics in the States that describes a new range of ultralight Dobsonian hardware for a mirror of your own choice and supply.
Cheap I reckon - the 13kg 14" is US$1,095 (which today is AU$1,027) plus $191 to ship via air to Australia. Even the 20" is around US$1,395 (which today is AU$1,308). The 12" is US$995. Pretty good any way you look at it.
Link:
http://www.hubbleoptics.com/UL14F.html
I'm not affiliated in any way - just passing on the news.