Any bowl needs to set flat to the floor without rocking. Shim as needed, though we tend to shim the back and try to pin the front of the bowl to the...
You would be looking at the Vespin II if you wanted to go with the 14" Unift adapter.
Same tank, but a different bowl that allows moving it back 2"....
I can't speak for all plumbers, but I would imagine most would have some knowledge of softeners. RainSoft may be proprietary enough that it can only...