IIRC the one you describe is called Sanichasse. I had a leaflet detailing the full range in the office the other day, I will try to find it tomorrow. Any decent plumbers merchant should have the full range. Incidentally apropos of another bit of this thread the wastewater one doesn't have a macerator and is thus quieter. Alternatively, you could bodge: the flexible pan connector on the standard saniflo will fit over 110 mm PVC pipe, so you could fit a short length capped off and fitted with a 40mm boss.