Welcome PV, and that area of Arizona is one of the few places in AZ I like.
Anyway, I'd go 30 - 40 HP (no one gripes about having too much HP), a HST for ease of use, a loader, a rotary cutter (a.k.a. brush hog, bush hog [actual brand name] for the tumble weeds. We have them in Colorado too. If you don't think you'll use a backhoe often, I'd rent a mini-excavator as a backhoe is a pricey toy, and a mini-ex is far more versatile. Make sure the tractor has four-wheel-drive (a.k.a. MFWD). A rear and/or box blade may be useful. I have a rear blade. A landscape rake may be useful; but I don't know in your case. If you can afford a cabbed tractor...GET IT! I'm tired of dirt and dust in my face in the summer, and freezing my butt off in the winter. A quick-hitch for your implements. Deere calls their version iMatch; but there are many manufacturers making them...some good, some crap. A set of pallet forks will be handy too.
At the risk of bursting your bubble, finding good used equipment may be difficult in AZ. Based on what I've seen at
Used Farm & Agricultural Equipment - John Deere MachineFinder and
Used Tractors For Sale at TractorHouse.com: John Deere Tractors, used farm tractors and farm equipment, tractors for sale, Case IH, New Holland, Agco, Kubota you will find that east of the Mississippi river, used stuff is plentiful; west of the river, it gets scarce. Therefore you may end up buying new whether you want to or not.
Test drive machines at the dealers and see which ones fit you and hubby well. Get a feel for whether the dealer is good or a jerk. You will need them for parts, and possibly service unless you like wrenching on your equipment.
Unless you like wrenching on your tractors, I'd avoid the cheap Chinese ones (a.k.a. Nortrac sold by Northern Tool, et al) as parts and service will probably be hit or miss.
As for the tumbleweeds and the fence-line. Yep, that happens here too. Fences make good neighbors; but they are a maintenance headache as far as I'm concerned.
Please post pics of your property! How else can I spend your money? :laughing: