Most all citrus is in jeopardy of catching HLB in the near future... a terminal disease with no cure. Until resistant citrus varieties are fully developed and released, i would not recommend planting now.

How high and wide do you want the hedge?

What about hop bush for the privacy hedge?

I'm sorry, I don't understand why you wouldn't call a local nursery for this question?

If your HOA allows, oleander is THE choice for The Valley as it needs no supplemental water after the first two years. It will, however, need regular proper trimming. Ficus trees are regularly killed by the "every few years" of extended below freezing temps.