Hi Brian,
FWIW, my thoughts on my decisions after running it for almost a couple of months ...
I am happy with 16 GB RAM, it very rarely gets to 80% in use and is usually in the range of 20-40%, 60% + with many files open in PS CC. When I had 6 GB, it regularly hit 85-90% in use, with consequent paging to HDD. The only surprise was that having ordered 2666 RAM (and that is what is fitted), I find it runs at 2133 - although the supplier says it will speed up to 2666 if it needs to, but runs slower when it doesn't (presumably to save heat build up), I have not tried to 'push it' to prove a point.
They gave me an i5 7600 and over-clocked it to approx. 4 GHz, which it runs at almost constantly, regardless of processor 'load', unlike my previous i3, which used to go up and down in frequency all the time (e.g. 2 - 3 GHz). So that speed increase, apparently, for PS CC, is more relevant than the number of cores, made the need for an i7 for me a non-issue.
Although I could, I haven't investigated the BIOS about either of these clocking aspects (RAM or i5) - "if it ain't broke ..." applies
The SSD does make one heck of a difference
So far; I am only using 83 GB* of my 500 GB SSD, so I probably could have saved a bit and gone with an SSD in the 250 GB area, as you have specified. * Documents, Videos and Images not being edited are kept on HDD.
Good luck with the build, Dave