Seeking non pressure assisted back outlet toilet

Hi

Does anyone know of a good(sadly, I'll settle for just decent) floor mounted, back outlet toilet, without pressure assist maybe something with a large flush valve? I currently have a crane with a pressure assist systems that went kaputt, it overflowed the tank after just three years. The expense along with what seems to be a relatively short lifespan and not to mention the potential explosive nature of the pressure units, well, I want plain old gravity. But I can't find any that are back outlet... help....