Most intersectional peonies have the similar if not the same foliage. There are only a few that are different. Which is why I stick with the tree and herbaceous peonies as you can find many with very different foliage. Many growers have stopped or will be stopping shipping for this year so you will have next season to visit gardens and area nurseries to actually look at the plants.

I think Amy from ILovePeonies.com is still selling and there's a percentage off, she has several nice Itohs. Brooks and Adelmans typically have last chance sales as well, probably others, too. Are you looking for a specific color of flower? Some of the ones that fade are really pretty, especially the ones with sidebuds, sometimes looks like completely different flowers on a single plant.

Maifleur is right about the foliage, Itohs do look pretty similar, but the ultimate sizes can be different so you might want to judge that way. To me Itoh foliage looks more exotic and tropical than herbaceous and they tend to hold their foliage longer and nicer here in zone 4b.