wall flange too low (floor mounted rear outlet toilet) & gasket choice
i have a dilemma which i hope you guys can shed some light on.
i have a gerber floor mounted rear outlet toilet that is sitting on tiled floor. apparently, the person who laid the tiles did not put into consideration to maintain the distance between the finished floor to the center of the flange to be 4". as a result, the rear outlet of the toilet is slightly above the flange on the wall.
i am trying to find a solution to remedy the problem without having to remove the tiles and the substrate and lay the floor again with the proper height.
i did a little bit of research and came up with 2 possible solutions and i would like to pick your brains and see if any of them would work.
1. replace the existing flange with an offset flange and hope that the offset would match
2. replace the toilet with something like the saniflo or caroma sydney smart. the adapter/pipe that comes with saniflo or caroma for connecting the toilet to the flange obviously would not work since it's made to mate the toilet to a standard 4" flange. but since both toilets have the rear outlet that is substantially higher than the standard 4" plus the toilet is set back away from the wall quite a bit. that would provide enough space to possibly install a fabricated PVC adapter that connects the toilet rear outlet to the flange.
what do you guys think?
in addition, i need to install a gasket and i have narrowed down the choice to 2: ZURN NEO-SEAL or FERNCO FTS-4 gasket. i like the funnel design of FERNCO but i am concerned about the strength of its adhesive especially when it's installed on an old toilet. the cement that comes with ZURN sounds more "industrial" and stronger, but that's perhaps just a matter of perception. so i would love to hear your experience and opinions on both of them or any other products that i am not aware of.
any recommendations and advice would be greatly appreciated.