Gerberit makes an in-wall setup for wall hung toilets. It's made in Europe and imported here.
It works with Porcher, Duravit and Toto bowls.
I'm thinking of the style with a 4" rear spigot outlet about 7" (centerline) above the floor. This seems a logical approach to a job where it would be a lot easier not to have to go into the floor.
Has anyone used these? Experiences? Where to get one?
The only common source in the US seems to be Sani Flow, which uses them with their macerator pumps for pump-up applications.
You have to differentiate between a rear outlet toilet which sits on the floor and one that hangs on the wall, ( I have never heard either one referred to as European style, however). Many manufacturers make both styles. Kohler's rear outlet floor mount is a Barrington. The wall hung models require a carrier inside the wall secured to the building's structure.