Veggie gardening is GREAT in Boise, but you are right, you will have to water. I don't know of any fruit or vegetable that can survive the summer heat (105+ degrees) without at least some water - it pretty much does not rain at all during the summer. Some do water with sprinklers, but I use drip irrigation, which I think is much better. Since you are not getting the leaves or fruit wet (and it doesn't rain) drip irrigation pretty much eliminates fungal problems and helps to reduce bug populations.

You are also right that there are quite a few vineyards in the area. There are also a lot of fruit growers in the area. I grow many kinds of fruit and find it more rewarding than veggie gardening. The dry climate and abundant sunshine make fruit growing relatively easy, but you do have to water. The only things you can grow without water are sagebrush and tumbleweed...

The other obstacles that I should mention are the cold winters and late frosts. It got to -8 degrees at my place and killed a couple of my new grape vines (established vines were ok). The last frost this year was May 24 (it hit 33 degrees), so you have to be careful when you set out tender plants like tomatoes and peppers. Also, in some years, it can go from 50 degrees to 90 degrees very quickly making it difficult to grow cool weather crops.

We are moving to Nampa in the very near future (Dec. 2013) and plan on growing our back yard into veggie gardens. We will start with a clean slate with a bare back yard. I have looked into what trees (fruit/nut) will do well there.
Any advice would be greatly appreciated.