Replace the floor first.
Then put the new toilet down over the new tile.
The ADA bowls work a little better, so go with the Eco this time.
I have two of the Eco in the home, they are working fine.
The difference between the Ultramax and the Drake?
It's mainly looks. The parts are the same and performance is similar enough so that it becomes a non issue.
I like the one-piece look, and cleaning is nicer too.