Most of your ADA toilets are 28" long, with about 3/4" behind the tank, at least in Toto brands.
Other brands tend to be a bit longer.
A good choice here could the the Toto Ultramax II, MS604114CEFG
A tall round bowl, which is 26.5" long would be a Toto Dalton CST733F
There aren't too many choices for tall and round.