Given the gap behind the tank, you may want to consider a one piece toilet. They are very strong and you don't have the tank "floating" on the back of the bowl. I think that Toto offers a 13" trap assembly that can bring the tank back to the wall. We have a Drake and my wife hates it. It flushes very well but there are ridges, one at the water line and up under the bowl rim. As well it has the exposed trap on the side which is a pain to clean. Sometime in the near future I am going to buy a skirted one piece. It will be a Toto, I'd suggest you make a point of demonstrating how toilets are cleaned to the boys and add it to their chore list. You are The Mom and while you will do everything for them, in this case I think you should " pin the tail on the donkey."

OK pricklypearcactus, you're making me do alot of research now.... Here's the 3" flapper, model# THU175S, used on Toto "G-Max" 1.6gpf toilets, like the original, now-discontinued Drake: That flapper, from what I've been told, can be replaced by model# THU140S, which was used on their "Power Gravity" 1.6gpf toilets that were their midrange models - G-Max was their high-end. Note the lack of a hole on the side, which keeps it from falling until the water level is lower, thus sending more water to the bowl: But both of those 1.6gpf designs have been discontinued in favor of two 1.28gpf flush systems: E-Max (on most of the "Eco" models) and Double Cyclone (on most of the "II" models). Now here's where things get complicated - all of these seem to use a whole new range of flappers - a quick search turned up at least three new ones - THU253S, THU277S, and THU299S. Amongst the changes, most (all?) of these have added a float that sits above the flapper. I don't know if the float can be adjusted or removed - haven't seen one in person yet. There's a picture of the flapper from the Eco Drake, which I think uses the 277, on Terry's site: (here). To get an idea of the difference, look at the parts diagrams for the old 1.6 Drake and the new 1.28 Eco Drake. Now see the difference in part #6, the flapper? It does seem, as Terry noted, that the rest of the tank (and the bowl for that matter) haven't changed - compare the other part numbers. Maybe all you need to do to convert an Eco Drake into an old-style G-Max Drake is remove the float, or at least swap to the old flapper, although Terry says on his thread that the flush valve is different too. There was a 1.6gpf Double Cyclone in the lineup until recently (on the Neorest, Soiree, and Guinevere) - I can't find what flapper they used. This is way more than I ever wanted to know about toilet flappers....

I understand that if you're used to toilet backs being very close to the wall, it might look weird to have one a couple of inches out. But in my house, one toilet's cover almost hits the wall, another is about 1 3/4" out and the third is a good 2 1/2" from the wall. I never even noticed it until I decided to replace them and measured the rough-in (by measuring the distance from the wall to the bolts). At first I thought I had one 12" rough-in, and two 14" - which wasn't at all pleasant because the selection of 14" rough-in toilets is dismal. It was only when I went back and measured again that I realized the toilets were not the same distance from the wall. I guess the builders just weren't consistent. So I don't share the sentiment of most commenters here, and would say that unless there's some substantive reason that no one has mentioned, and you don't think it's going to bother you personally, go for the 12" rough-in Toto.

I should add... the current space is just barely over 11.5" ... I'm hopeful the 1.25"-gap Cimarron would have enough leeway in the hole position to fit, but would check that out with my tile guy and plumber before buying. (I'd strongly prefer the Santa Rosa toilet if there's an option to use that though.) One other possibility I suppose is going with 1/4" backer board but I'd prefer the 1/2" as we have to hang a big mirror on that wall.