The unifit might give you enough room for an elongated bowl, because it moves the whole toilet back.
Edit: You know, I didn't read the dimensions carefully enough. I'm wondering what would work in the Toto line even if the rough-in was 12". The Drake round bowl is 26 3/8" just for the unit, and another 1/2" or more behind it, when placed on a 12" rough-in. On a 14", forget making 26 1/2" (you're saying that's from finished wall to front of toilet, right?). As Jim notes below, most of the Unifit-using Totos are at least 28" just for the unit.