Hi guys. I need to replace a high level cistern/pan, for either a low level toilet or preferably a close coupled toilet. The big issue with this is that the 4in drain to it comes up through a concrete floor, which is 100mm from the back wall to the centre of the waste outlet in the floor. I can't seem to find a close couple toilet that has the required clearance at the back of the pan. Do any of you knowledgable folk know of a loo that may have the clearance I need? I've looked at wickes bog in a box but the pan would foul the drain when pushed fully back to the wall. Any advice would be great. Cheers.