Hi, Julia, welcome~!
I have grown "Kim's Knee High" and it has increased steadily and been quite care-free. Also, like you, Magnus is a staple.
I've had poor results from White Swan. But I am in Zone 7A.
"Sundown" is an interesting variety and it is hardy to Zone 4.
Here it is in our database
Coneflower (Echinacea Big Sky™ Sundown)
