Contact your local county agricultural extension agent. Every state has an Ag school and that ag schoo by federal law has county extension agents in every county. He can give advise on food crops and ornamentals.

We're in southern orange county, also on a hill with open views, but probably not as hot as where you are. My backyard is mostly tropical... here's what is doing well in my back border:

Giant bird of paradise
Regular size bird of paradise
Cannas -- especially Tropicanna
Hibiscus
Confederate jasmine (mounding, on the edge of the border)
Roses (tropical colored floribundas, like Disneyland and Tropicana)
Daylilies
Succulents like aeonium and bulbine frutescen
Bright colored salvia like chiapensis

In the shadier areas, I have elephant ears, bananas, croton, philodendrum

Here's a picture from last year, the border has really filled out since then.

best of luck and have fun!

Here is a link that might be useful: {{gwi:1302541}}

I actually saw the most amazing tropical garden at an open house down the street - so I got a lot of great ideas. They kept it less lush (the wind takes out a lot of the gorgeous broad leaved plants, but here is what they used.

Giant Bird of Paradise
Regular Bird of Paradise
New Zealand Flax (purple)
Coral Bells (Purple Palace)
Horsetail
Cannas
Plumeria (they were small, so may be just for showing the house, but I have seen some Plumeria live up here, just have to know when to cut back on water)
Papyrus
Azaleas
Wisteria
They used a lot of blue slate and blue mexican beach pebbles... anyway, I like things much more tropical, but I think if I start there, and maybe add some bamboo and gingers I might have a start.
I also am going to find a place for my night queen epiphyllum - :)