It will grow beautifully in your zone, Cal. I've always bought the plants in six-packs at a local nursery. The Amazon offer looks good, but 5,000 seeds????
I was thinking of growing it from seed this year because the need for social distancing might keep me out of nurseries. I found it on the Baker Creek site.
The grandifloras are a taller variety, and planting 200 seeds sounds more practical to me.