Do you have access to beneath the floor? Is there something in the way that prevented them from originally using a standard 12" rough-in? If the restriction is a door, would it be possible to rework that doorway to be a pocket door or an outside surface door (similar to a barn door)? Either of those can work well, and makes a small room much more manageable. 26" is short for any toilet, and then when you throw in the 14" rough-in, you've got even more problems. There are some offset flanges that work, but the more common one does not work well at all. But, if you have room to use one of them, you usually can move the whole thing to where it needs to be in the first place.