Our local nursery Pikes carries Monrovia grown plants. They're expensive, but I get instant gratification. They only sell them in the spring, so I leave them potted, and plant them in the fall.
Our HD and Lowes will also carry plants in the spring in 1 gallon pots. I've gotten a few of the more common plants from both stores. A not so common plant that I got from Lowes is Wladislawa.
I've looked at CharMarron's site, but I had not heard of Select Plus. I'll have to check them out.