Hmmm...just spent 10 minutes doing an Internet search for saddle fitters in Arizona. There is one listed in Phoenix, and I might find more if I did some searching. But I'm south of Tucson, and I don't know what they would charge to come 150+ miles to see two horses.
The Horse's Pain-Free Back and Saddle-Fit Book Amazon.com: The Horse's Pain-Free Back and Saddle-Fit Book (9781570762925): Joyce Harman DVM MRCVS: Books
And it's western saddle equivalent Amazon.com: The Western Horse's Pain-Free Back and Saddle-Fit Book: Soundness and Comfort with Back Analysis and Correct Use of Saddles and Pads (9781570763892): Joyce Harman DVM MRCVS: Books
Are available for $20. Reading the English version was a bit frightening - I kind of got the impression I needed to buy a custom built saddle and have it professionally fitted several times a year - but it DOES go thru the basics in enough detail that MOST riders should be able to assess their own horse & saddle.
Happily, both of my horses have nearly identical backs. We went thru 3 western saddles before finding a Circle Y Arabian that fits them about as well as a western saddle can. I own 2 Bates saddles with CAIR, and both fit OK, although the AP version is a bit flatter than I want and may go up for sale. The horses and I both seem to fit better in the jump saddle, although I'm sure I look weird riding it with long stirrups and a navajo blanket underneath. We also have a Down Under Australian saddle. With any of the saddles, I can ride them with a thin cotton pad (with no padding). I figure if my 170 lbs on a saddle without any additional padding doesn't bother them, and with even, balanced sweat marks, then I'm probably OK. The women in my life are a fair bit lighter, so the test is tubby hubby....
I've only been riding 2 years, but our mare is both patient and expressive. She won't buck, but she'll let you know if she isn't happy - and she always has a reason. As a beginning rider, sometimes it is me. Sometimes it is the tack. Sometimes she has a sore. But if she raises her head, swishes her tail and tosses her head a bit, there IS a reason - and it is up to me to figure it out.
Calling out a professional fitter isn't a very realistic option for a lot of us. Listening to our horses, and asking for help when there is a problem, is not an option either - it is a requirement for anyone who wants to ride. I suspect the last sentence, at least, is one we can agree on.