Zone 9 is typically considered the upper reaches, but if located carefully, you may have luck with them. A consideration in your frost free climate is that there is insufficient cold for a period of dormancy and vernalization - a common problem for a large range of perennials in higher zones.

As for location, have you tried Roger's Gardens in Newport Beach? A really first class garden center with an excellent plant selection. If they don't carry a selection it will be because hellebores are not well-suited to your very temperate zone.