Hi,
Seed saving would be the same for all echinacea. Depending on the cultivar, the seed size or color may vary, but essentially they will be the same. It is possible that you could find some that are sterile or near sterile as cross species breeding sometimes has this effect. So if you don't find seeds with some, don't think you are doing anything wrong.
I'm assuming you know this, but for anyone reading, seeds saved from these varieties will have seedlings that vary as they do not come true from seed. But if they did come true from seed, coneflowers must be grown in isolation for seed purity since they cross pollinate so readily.
Hope this helps,
Remy

I was wondering that too,so i guess is not worth it since I payed $3.50 for a gallon size plant:)

Anything is worth the try as if they put on seeds you do not have to worry about when to harvest once they are dry as they will not fall off. Some of the newer varieties from what I have read do not produce any seeds and have to be divided to produce more plants.