I am considering moving to northern Arizona or New Mexico and I am wondering about the astronomical potential. Specifically the Flagstaff area and the Taos/Angel Fire/ Eagles Nest area. I have checked the dark sky maps but I am also wondering about the planetary potential. I currently live in a Bortle 2/3 site but the seeing is marginal at best. This is good for deep sky but not so good for the planets.
If you are currently in a Bottle 2/3 zone then you won't do much better in any of the locations you've identified. Without knowing where you are currently located it's hard to say more in comparison, except that the combination of altitude and likely lower humidity will be a win for transparency while perhaps something of a loss for seeing. Planetary observing being a bit more sensitive to seeing than transparency (at least in my experience/estimation) you may find that trade-off a wash. On the other hand, you don't get many more clear nights/year, which is really quite nice.
In any of these areas the key is going to be getting your property sufficiently well out-of-town. For this purpose you really need to visit and take some night drives to the the relevant neighborhoods. The necessary distance may not be as great as you think: in all the NM sites you indicated, the combination of altitude and (very) low humidity keeps the light domes modes and well-confined. Twenty miles from the population centers may be sufficient.
To give you a sense: I'm located outside Santa Fe to the SE (on a map along the 285 corridor south of I-25). The lots in my area are typically 1 acre or larger. From my lot, where I built an observatory, my SQM readings are typically 21.2+/-0.2. Light domes are from Santa Fe and ABQ. Owing to the altitude and the low humidity these are exceptionally modest for the size (ABQ) and proximity (SAF) of the population centers.
My impression of Flagstaff - I drove through on the way to the Grand Canyon Star Party in 2019 - was that it was a great town, but that it was situated in the mountains in such a way that you might find it hard to get a property that didn't have a significantly obstructed view over a significant fraction of azimuth. Hopefully someone from Flagstaff can speak to that.
As regards Taos: it's located in a large basin; so, assuming you can get your property sufficiently far from the town center you should be in good shape. I don't know the Angel Fire area geography. It does have a roughly 1500' advantage in altitude over Taos and Flagstaff: at 8,400' is not to be sneezed at. I've known people who can't handle the 7000' altitude of Santa Fe/Taos/Flagstaff and have had to move to lower altitudes.