I'll give you a version of my standard speech......
Without knowing more about how you use your phone, it's hard to make a specific recommendation. However, in general, I would recommend that you buy the latest model your budget allows. That will give you the longest supported lifespan for the device. Since you keep your phones a long time, I'd go with the iPhone 14 rather than the 12.
If you're not in a hurry, keep an eye on the Apple Refurbished site. They don't have an iPhone 14's today but they do have iPhone 12 and 13s, including some pro models. What they have changes often. I've bought my computers from that section of Apple for years and can tell you that Apple Certified Refurbished devices are indistinguishable from new except for the packaging. And have the same warranty as new. If you do find what you want, be prepared to order it right away or it may be gone.
Refurbished iPhone Deals - Apple
Honestly, there isn't really a wrong choice here. Anything you get will be such a leap forward from what you have now (loved my iPhone 7!) that I think you'll be happy.