I haven't seen that you've commented yet about your usage. I assume you're in either the beginner or casual photoshop groups, since I'd imagine most "pro" photoshop users would have a rough idea of the system requirements they need.
Speaking from having used Photoshop, and Lightroom (now Lightroom Classic i.e. Lightroom the full version) far more, 16GB is fine. The software will also utilize whatever resources you can throw at it- cores, clockspeed, all of it. And for this kind of stuff, real cores trumps virtual hyperthreaded cores, so the 6C6T version would definitely be my recommendation.
Where you'd want more: video. You have to do a lot of work, shoot hundreds of frames, to really bog down LR; or try to combine dozens with various types of bracketing (focus, exposure, stitching) to really bump up against 16GB and make the CPU squeal for a significant period of time.
But video processing will have you waiting until after dinner, and it'll hit storage too; and if you hit the RAM ceiling? Stop talking about percents slower, and start multiplying by integer factors...