Building an expedition touring bike

[Smileyguy]

I was looking at the Roberts Roughstuff:

http://www.robertscycles.com/p_touring.html

And Thorn Nomad:

http://www.thorncycles.co.uk/nomad.html

Both are tourers designed for much off-road use too.

There really only are a few bikes in around in the UK specifically designed for this kind of use, and they are all custom-built, and expensive, which why I'm looking for an alternative solution.

The way I see it, a mountain bike wouldn't be as good on the road, but with a change of tyres it'll be fine, I reckon. At least I hope so!