China asters aren't for everyone, but they should be more widely grown. They prefer to be planted out under short day conditions, when they send out roots, grown on under long days, where they gain height, and then finished under short days where they initiate bud and flower.
Planting in March/early April will allow this natural progression. They enjoy cooler temperatures, but are not frost hardy.
The Standy Series from Benary are large flowered and resistant to some of the wilt diseases that can attack asters.
Tower is a peony flowered strain and appears identical to the Duchess strain (that we can't seem to find the breeder of). Chamois is the that soft apricot color that is inexplicably still popular. I am searching for an image. Google will help until then. You'll like them.
From Gro 'n Sell's cut program, Ballon and Crown series are both offered in mixes including the full range of colors.