Goji (lycium barbarum) is drought tolerant, hardy and very highly revered in chinese medicine. Leaves & berries. The plants are attractive as well. There is a variety that grows wild in arizona. I've got some starts from goji berries bought at the health food store.

Pomegranate is another dryland survivor, with a bit of an ornamental look, though they will fruit better with a little extra water. Easy to propagate from cuttings.

Can't help you with plant reccomendations but this book is amazing. Sounds like you may already have it judging by the plans you have for your slope. Good luck.

http://www.harvestingrainwater.com/

I just planted Serviceberry in my xeriscape, apparently once established it is XX and has small tasty fruits rather like blueberries.

Also, maybe asparagus.
I water mine weekly in the early spring, but once I'm done harvesting let it go a couple of weeks between watering and it does just fine.

I would think about putting in some rosemary and sea buckthorn, both of which are pretty drought tolerant.

Here is a link that might be useful: Edible Garden

Prickly pear cactus has delicious fruit, and you can eat the pads as a vegetable (taste like green beans and asparagus). It also keeps critters out of your stuff if you plant it like a fence. You will need heavy leather gloves!

A lot of people dry farm zinfandel wine grapes planted on a hill, staked like a tree, and pruned to look like a small tree. The nature of the vine is to grow downwards, so once a trunk is established, it looks like a weeping willow sort of. You can get zinfandel cuttings free from UC Davis in the spring, but order soon. Not sure how cold tolerant it is, but it thrives here in the low desert!

I'm not sure if it will grow there,but Autumn Olive may be something to try.
Here is a snippet from Dave's Garden about it.The autumn olive prefers well-drained, poor, sandy soil and full sun, but will tolerate some shade. It prevails after a fire, returns stronger and bushier after cutting, and is drought tolerant after established.[2][4] The plant roots are like that of a legume, in that they have nitrogen fixing nodules and are used in orchards as companion, or "nurse", plants that help enrich the soil and protect black walnut and fruit tree seedlings until they are established. Brady

figs, sea buckthorn, goji berry, Pomegranate, and Prickly pear will work great but just like anything else you'll need to establish a good root system before you notice any drought tolerances from any plants. So mulch deeply and and water when needed for the first 2 years or so.you may need to shelter them from really hot days by adding a few taller non edible plants native to your area. Also build your soil with rich organic matter to improve it's water holding capabilities and you should be good.

you may want to think about some kind of cover crop that grows well in your area and start incorporating some organic matter into that sand you got. you can reforest a desert but you really need to start with the soil first. you can plant 500 trees and shrubs but without water holding capabilities your going to loose a lot of plants when you cut off the irrigation regardless of how old they are. if you can't find a cover crops that grows well in your area you can find native weeds that grow lush on the side of the road and get a few seeds and plant them in your yard. then till them in before it self seeds. This can be a bad thing for invasive spices but do a little research on the plants you find and you should be fine. even weeds produce organic matter and if your soil won't grow much of anything without irrigation I'd take what I can get just to get the soil built. after about 2 years of building your soil incorporate plants slowly and add plenty of compost to the holes you dig each time you plant something. also much deeply and try terracing you slop a little so the mulch don't wash away. I'd say at least 6 inches and use a layer or 2 of cardboard under the mulch so no light ever gets to the plants you don't want anymore.

What about this one? I don't know. Just looking for edibles to grow on property we are buying in So CA.

Chinese HackberryCeltis Sinensis
A hardy and easy to grow plant. Tolerates drought; any soil; gusty winds; smog; sun or shade, but does not like heavy fog. Makes an attractive, low-maintenance street tree. Deep, non-invasive roots rarely cause sidewalk problems. Disease and pest resistant. Berries attract birds. Tree grows to10m in cultivation. Small green flowers are borne in Spring followed by small, sweet, edible fruit which are a dark-orange ripening to red-brown.