Best way is to pick a brand of toilet and go to their website for the specs. For instance, you could go to Toto here: http://www.totousa.com/Products/Toilets.aspx
They have some options to filter the choices based on bowl shape, flush rate, etc. If you check the "ADA Compliant" box, that will return the taller bowl results. Once you find one that you may be interested, click on it for more detail. There will also be a tab called "Downloads & Resources". Click that and you can download the spec sheet for that toilet and get all of the dimensions.
BTW: the price listed on the Toto site is usually a fair amount higher than what the toilet will actually cost you.