The Drake ADA doesn't adjust, it's a standard 12" rough toilet.
Most 14" toilet combinations are really 12" bowls with thicker tanks.
As long as there is room, using a standard 12" would be fine.
If you want to pull the bowl back toward the wall, then there are models that use a Unifit, some are for the 14" rough.
Toto Llyod has a 16.125" bowl height and the 14" unifit can be ordered for it.
Toto Nexus is 16.125" bowl and will work with a unifit.