Hi. I'm in LA too. Can the branches be wider than 12" ? Do you need coverage low or just high for the upper level windows? If the plant can only be 12" wide its really too narrow of a space for total coverage because you will only have the stalks (called culms). If you only need coverage higher up and you can let the branches grow out then you have a better chance of coverage. I don't know of any bamboo that will stay only 12" wide at the base. If there is a deep barrier (1' for a clumper or 2' for a runner) then the bamboo will stay where you want it. Or you can put in bamboo barrier and not have to worry about it. Otherwise I would suggest a fence and a trellis/lattice above it, possibly with a vine. For narrow, very upright, shorter bamboos Check out Thamnocalamus, Fargesia nigra, Alphonse Karr, Chimonobambusa marmorea (runner) or maybe Tootsik (runner). Just Google them and you will see lots of photos and info.

10 feet or so is more doable. But not that one. Bambusa Malengensis grows to about 35 feet. Putting it in a pot is not going to make it happy. If it only stays 10 feet it's going to be because it very unhealthy and starved from the tight space and wont look good. Plus clumping bamboos exert a tremendous amount of force. I bet it would eventually crack those pots. If you've ever seen bamboo that has stayed in it's nursery pot to long you'll see it split the pot right down the sides. That's if you keep it in only one season to long. Here is a photo I found of this bamboo (on bambootexas.com). I don't think you're containing that in a pot. Plus clumpers like that fan out very wide at the top. It would be like a huge sail catching the wind. I'd imagine it would be blowing over in no time as it got bigger. If you really want something in pots then you should try putting them in plastic containers and then setting the plastic containers inside the ceramic ones. That way a few years down the road you can take them out and divide them easy. I really think you'd be happy with Phyllostachys aurea as a privacy hedge. It will grow tall pretty fast in a pot. A few years down the road if it looks distressed then divide it. Ultimately I think you'd be really happy with it in the ground though with a barrier (or a planter). There is nothing like being behind a well grown bamboo hedge. It's so peaceful and less anxiety from the neighbors. Hearing the sound of the leaves moving in the wind is calming. You can do a container and it will look great, just a little more work every two or three years. The bigger the container the less often you'll have to divide it. This might work better for a container screen to though: Pseudosasa japonica I don't know how long it takes to get tall though. But might be much happier in a pot. There are probably a few others we can find.

Anything in pots or planters is likely to need repotting at some point. So if you use climbing plants that get all through the fence you will have to cut them off in order to get them repotted. And as mentioned with climbing plants being used on an architectural feature like a fence there is a need for consistently undertaken pruning and training in order to get the plants to assume and retain the desired size and shape. In addition to the regular cleaning up, fertilizing and watering that any kind of live plants used in your situation would require. So I think instead you should continue in the general direction of the fake fig panels, wherein you identify and implement some kind of material or product other than living plants that will still make it so your fence is not see through. It doesn't have to be something that looks like plants, just something that will produce a screening effect. And look acceptable to you.

I am familiar with that area. Virtually any citrus can grow in Los Angeles. Due to it being a very sprawling developed city, there is a heat island effect. In the old days they could grow orange groves in that area, but occasionally they would have winters that could damage the orange crops, so they would actually sometimes light big fires around the trees to help keep them warm through the coldest nights. Temperatures in the area do not get as cold as they used to 70 years ago, due to the extensive development and suburban sprawl. Mandarins and Meyer lemons will be just a little more cold tolerant than oranges and regular lemons, and should have no problem at all. (Though Meyer lemon tastes different than regular lemons, so be aware of that) There are certainly ways to plant trees on a slope. But the trees will most likely have to be irrigated in the summer. In that climate, the fierce hot dry summers will be more of an ordeal to plants than the winters. It is classified in climate zone 10, so there are many borderline tropicals/subtropicals that can be grown that cannot even be grown in the Northern part of Florida. You can grow mango trees, for example.