Do you want evergreen trees or deciduous? The xChitalpa tashkentensis Pink Dawn is about the size you want for your larger tree, and is longer blooming without the messy looking seed pods of the Desert Willow. Smaller tree might use an Oleander trained as a standard, or you might consider the rather common but always beautiful, fast growing and long blooming Crape Myrtle. Another well adapted for heat and drought smallish tree might include Rhus lancea or an Acacia podalyrifolia or Acacia cultriformis. Narrow
growing screens up against a fence might include Grewia
occidentalis or Tecomeria capensis; both take heat and can be kept trimmed to 6 to 8 feet tall by 2 to 3 feet wide if kept clipped as a flowering hedge.

we have decided to go with 1 podocarpus tree, 1 pink dawn, and 1 muskogee crape myrtle tree.

and for the privacy screen, grewia occidentalis!

thank you bahia for the great suggestions!

what would you suggest i use to mix with the soil from the hole? maybe garden soil or some type of compost?

thanks

Be aware that while the Grewia can be kept fairly narrow if trained as an espalier, if not so trained it will grow as a wide bush. I'd suggest starting off with espalier trained 5 or 15 gallon size from the nursery. This shrub may also drop some foliage in your freezes, but is generally safe to use as an evergreen hedge if you seldom drop below 27ðF or so. Your much warmer winter days may give you better evergreen character in winter, they can tend to thin out a bit in colder winters here in northern California.

As to amending your soil, it depends on what you have to start with. First thing is to dig any planting pit at least 2 to 3 times wider than your container size, but no deeper, and flood test to see that water drains fully within a couple of hours. I generally do amend the backfill 50% with aged compost or similar, but current horticultural research says this is unnecessary, and a surface application of compost as mulch is more beneficial, repeated once or twice a year. I'd suggest you get a copy of the Sunset Western Garden Book as a good general reference for your gardening and plant questions, it should answer most any gardening question you might have.