Keep your 10s as they will work for some things. Worry about potentially upgrading them at a later date.
For about $300 you should be able to get a fully functional tripod and head. I still use my first tripod, a Manfrotto 290 XTRA CF, for glassing; you can get the aluminum version for about $150. Go with whatever tripod/head setup that makes sense for you.
Get quality 15-18x binoculars as this is what you will be using the most for glassing typical country in AZ. The Leica Geovid R 15s are very good and have a built-in rangefinder. The Swarovski SLC 15s are synonymous with glassing for Coues. The Vortex Razor UHD 18s are nice. All can found, new/used/demo, for about $2K or less. Don't be afraid to pick up the phone, call around, and ask for their best price; do reach out to CameraLand and S&S both of which are Rokslide sponsors.
Now you will need a binocular adapter to attach your binoculars to the tripod head. Lot of options out there at various price points. Some may or may not depend on the optics you have. Do plan on being able to mount both your 10s and 15/18s.
You do not need a spotting scope.
It is a personal preference whether to bring multiple pairs of binoculars. I only bring either my SLC 10s or my SLC 15s depending on where and what I am hunting in AZ; I never bring both.