So, this is what happened...
After doing a lot of research, I concluded getting an I7 over and I5 would produce little benefit in Ps, the only application I use that is CPU hungry. For the time being it appears that 16gb is enough for the way I work. Big panos are rare and complex Ps projects are almost nonexistent. The motherboard I selected is inexpensive but get great reviews. The local Microcenter gets a few in every two weeks and they sell out immediately. What it lacks is a fancy power supply for extreme overclocking and USB 3.1. Right now I have no USB 3.1 peripherals and don't expect to see any for a while. USB 3 is more than fast enough for the external spinning drives I use a lot.
So the I5-6600k, Asrock Z170M Pro 4s and 16gigs of DDR4-3000 totaled $379 at my local Microcenter, including sales tax. I did not need 3000 speed memory, but it was less expensive than the slower stuff. Everything went together quickly. My case is so old that I had to modify one of the headers as the standard had changed a bit. The CPU overclocked to 4.4 ghz without a lot of voltage increase and runs reasonably cool. It will run at 4.5, but it isn't worth it in terms of voltage increase and heat. In order to save time I used my existing Win 10 setup although it had to be reactivated with M$.
Although it is nothing like years ago when I upgraded from a Lynnfield to Sandy Bridge, the increase in speed is a bit better than I anticipated. When I get around to it, I can install an M2 SSD which is twice as fast as the already fast Samsung SSD I have now. The old MB will go in a case that now houses the slow 7 year old Lynnfield machine.
