replacing toilet with concealed cistern

[heron8888]

I want to replace my toilet (armitage shanks) the cistern is boxed into the wall behind, and I want to keep this, what type of toilet do I buy?
will the pipes line up as they come through tiled wall?

 

[muggles]

Get a back-to-wall pan. There should be a little leeway on the soil (outlet) pipe, but you won't get any on the flush (inlet) pipe. If you take measurements to the centres of the flush and soil pipes and go to a plumber's merchants they'll help you find what you need.