Hey Nigel,
I got your email too, so I'll try and reply to that... I'm thinking a good place for you to look for some advice would also be
www.newcougar.org , our US Cougar brethren. They'll have a lot more experience with such matters/issues.
I don't know of anyone who has replaced any of the above components in their Cougs, but it could be something we should keep in mind if you've had a problem in this area.
Not sure if you've tried
www.nolathane.com.au for bushes? But suspension components are virtually non-existant for us down here.
Dan