What is the water distribution? Long, hot, dry summer? Or does most of the rain come in the summer? Current water retention? If you dig down in the driest part of the year, how far down is the soil still damp?
If the soil remains even slightly damp, with 31 inches of rain I wouldn't be concerned about a well as long as you can keep the water on the land. You may need to focus on trees and varieties that deal well with periodic drought, but you get plenty of water. I get less than half of the water you get, but under deep woodchip mulch I can grow many crop annuals without supplemental water in a desert summer (30-40c, 85-105f). This also depends on the water holding capacity of your soil. Mine is almost straight sand, so with any amount of water retention you can probably do better. Dry gardening is a learning curve, so if you don't have the time or the inclination you may want to go for the well anyway. However, I would suggest that you not make the well a long term part of your plan. You don't want your whole project to die if something interferes with your well.
Soil clay? Sand? Loam? Your soil is going to largely determine what you can do and in what order. If you need to do a lot of soil remediation your herbals and annuals are probably going to go in first, as they will have the easiest time adjusting. If you're planning to seed the trees in place, that also makes a difference as the plants won't have to adjust to your conditions. Or rather, only those that can deal with those conditions will survive their first year.
Earthworks, water, soil remediation. After that depends on your goals.