@Nick can I get a link to that nursery's website? Can I see a photo of what the material looks like out of the bag? Do you need to filter at all? There are many rockeries around here that sell fir bark by the cubic yard, but it is either too large or includes fines. The amount of work I would need to do on it far exceeds the extra cost I am paying for a pre-filtered product

@Sara Malone Zone 9b I think half a ton would keep me going for a while. I have looked at some of the better-known supply companies, but the problem has always been that they have the "fines" included. Typically these are base rock products. I found one candidate with a good photo. The problem with these landscape supply companies is that they have no datasheets for the products they sell, so I have no particle analysis. The #2 Olympia Sand on the linked page is the only sand I could find out of 10 landscape suppliers that visually looks close to what I need. Do you think this is horticultural sand?

The "best" variety for your area would be the native species, Myrica (now Morella) californica. It is well adapted to the west coast climate and periodic rainfall/drought conditions. It is used frequently for privacy hedging, even as far north as up here in the Puget Sound area (there are some native colonies of it on Vancouver Island), and is not fussy about soil conditions. Needs water to establish well but once established, it is very drought tolerant and should not need any summer irrigation. Full sun will provide the densest growth but shearing or pruning will also help the shrub to 'fill in' :-) Finding them in the size you want may be difficult. Very few growers offer them in that large a size........the demand for the plant is great enough that they sell them off long before they reach that size. But it can grow pretty rapidly....as much as 24" per year....so even a smaller shrub to start with will make a significant presence in just a season or two. Will easily reach your 10' height (can get as tall as 30' but rarely in a garden setting). And pretty much pest and disease free. FWIW, it is also rare to find myrtles other than the native species for sale in area nurseries. They just don't do as well here nor is there much demand. The native will win out every time.

Manila is the taller one. About 11 years old. The Ataulfo is fronting it. It was started from seed over five years ago,pushing six. It had a LONG period of almost no growth adapting from pot to dirt. It had very compact flushes and I even came close to digging it up. Then,it took and has been fast for local conditions of mild summers,cool summer nights (60f).