I have already bored people in this forum with all the reasons I think festiva maxima is the best choice of all herbaceous peonies. You could probably use the search function to find discussions of the various cultivars, if you need to make your decision in a hurry.

Since these are all herbaceous lactiflora peonies, they will all be about the same size, around 3 feet high. The clump will grow wider over the years, but can be divided.

I guess it depends on what color flower you are looking for. You can look up pictures for these peonies at Carsten's Peony web site. Go to "The Peony Database" in the middle of the page, and click on the letters to find the name of the peony you want to look up.

Here is a link that might be useful: Carsten Burkhardt's Web Project Paeonia

You can also look them up at helpmefind.com
We had Festiva Maxima when I was growing up and it was a gorgeous peony. I think the pink one we had was Sarah Bernhardt- also a beauty if you like pink. I can't help w/ the others, but Duchess de Nemours is one in a collection I am considering ordering-it is supposed to do well in the South. Good luck! Brandy

I would be very careful about trading. I fell for this about 3 years ago. Dug this man a great tree peony for only freight. Never heard from him again. the address was Tulsa, Ok.