Whilst hunting through some bits today for parts for a MonSHED eo (sorry, must gets that tourettes looked at) I decided to dig out what I could which may benefit you lot.

I have VDA leads for those lucky enough to have the plug, Quad Lock interface leads which utilises the audio input on the back of the radio aswell as supplying power, the older ISO plug (2005's) again which utilises the audio input on the back of the radio aswell as supplying power or for those who don't want to spend money I have the pins which push into the quad lock plug so then all you have to is source power.
Bracket wise I've only come across some console brackets but I'm sure I should have an air vent bracket somewhere. Ah infact I just checked http://shop.dashmount.co.uk/vauxhall.asp & realised I came across a bracket & thought what the hell is that for & threw it to the back, yes it was an air vent bracket Oh well it's in their somewhere.

Looking at £15 / lead posted & £10 / bracket posted
Think this is a savng of £10 on each IIRC

Do have bits for other vehicles knocking around so if you need any just ask & I'll see what I can find.