I got a lot of help from people on here and on Volkszone which was very useful indeed. The pdf document by Toby Erkson was by far the most in depth account for how to tackle this nuckle bashing engine bay!
Here are some photos of the completed conversion. I'm pretty happy with it overall, although in hindsight I already wished that I'd gone for a more powerful alternator to have some excess amps lying around!
Mocking up
The LHS mounting post
The RHS adjustable bracket
I didn't have to chop any part of the fan belt housing and the original cover fits back as it should.
It's now been fitted since July 2012 and I'm glad I made the change!
Hope it helps someone!