Thanks all for the input.
I think that I will use one of these : -
http://www.betterbathrooms.com/showe...ide-rail-pack/
or summat similar.

Now - if I mount it into a corner with two solid brick walls, how best to
pipe up to it?
Is it usual to create a false wall and tile it, or cut a channel for the
pipes?

Sorry for the stupid questions, but this is one of the few jobs around the
house that I have not yet tried to do.