Whoa. STOP. A rough-in is correctly-measured from the
finished wall to the center of the closet flange. Not from the studs, contrary to what one (otherwise-excellent) post in this thread says. Sorry, but that's the official, actual, architectural truth.**
Now, that said, many 12" rough-in toilets don't use the whole 12 inches. They're just saying that they will fit on a 12" rough in. And the few that do require the whole 12" usually make that very clear on the spec sheet, often in capital letters. But some do. Most, as noted above, have a little play, or even more-than-a-little play.
Donn, you are misreading those spec drawings, so I would stop and follow Reach4's advice to reread them or you're going to end up in tears.
Usually, the most-important (i.e. smallest) dimension is from the tank top to the wall, or from the protrusion towards the wall that is directly under the tank. If you just look at the base, you're going to have a base that fits fine, while you're slamming the back of the toilet against the wall finding that it won't fit.
The classic toilet that has significant space between it and the wall is the original Toto Drake with the original tank, Model CST744E, which can fit on just-less than 11". Many people really like that Entrada that you mentioned, as well, and it's a good value, but make sure you have the room.
Also recognize that toilets are made out of clay and baked in a kiln. Some brands use better clay than others in terms of the consistency of their water content and thus what the "baked" size will be. Toilets shrink dramatically in the kiln from the formed clay to the final product. Like 15 percent or more. That's enough that if they don't shrink consistently, the output will vary. Toto is the most-consistent in terms of clay, and thus the most-consistent in terms of finished size. Toto is also the most-consistent in terms of the finished product not varying by factory. You can have a Toto bowl and tank made in Atlanta and a Toto bowl and tank made in Vietnam, and you can mix and match and never be able to tell where one or the other came from.
But because you're dealing with something where some are going to be bigger than others, I wouldn't put myself in the position of needing every 1/8" on the spec sheet. Similarly, I wouldn't put myself in the position of wanting to be sure that the toilet has no space between it and the wall. You're going to find that, out of the box, you can't completely count on either. Somewhere on most sheets it will explain that one should expect variation from toilet to toilet to toilet of the same model from the same factory. Because an experienced installer can cheat the toilet a little towards the wall or a little away from it, this helps some to get you the look you want.
Bottom line: read the spec sheet carefully, and be sure you have enough room. You should be able to find a toilet you like that fits.
That looks like a very-nice job you have done so far, so we would love to see a photo of it when you're completely-finished! And don't hesitate to come back in the interim.
**For reference, in case people don't trust New Yorkers:
About Toilets (americanstandard-us.com)