I spoke to many different companies before making a decision on what to go for, unfortunately many of them were bluffers and had little understanding of what was best suited as they are more used to people asking about performance for games and to be fair a few of them admitted that. A lot of them kept banging on about gpu etc.
I also spoke to Adobe and they told me that at the moment Photoshop can make use of up to 8 cores depending on the task. After speaking to Adobe and having a better idea of what I was looking for I again spoke to a some of the computer companies. I fell lucky with 2 of them one was very knowledgeable on photoshop and lightroom and he sent me through test data on various things, the other was a wedding photographer who had went back into employment because of the current situation. They both recommended the 5800X as being the best option in terms of performance vs cost etc.
In the end I decided to go for the 5950X as Adobe had advised that going forward as the software evolved over the next year or so they would be able to better utilize the newer processors. Also my eldest daughter occasionally uses the computer for video editing which will increase over the next year or two as she has chosen moving image art as one of her G,C,S,E's, the extra processing power will help with that. The cost difference wasn't huge and it just so happened that the supplier I decided on in the end had the 5950X in stock, they are very hard to source at the moment.
A friend of mine is a wedding videographer I had also chatted to him about what spec to go for as he had recently bought a couple of new workstations himself, he gave me a graphics card he had going spare an Nvidia GTX 1660 Super which is supposed to be a decent enough GPU for video editing. That meant I didn't need to buy a GPU so the saving there made up for the difference in cost between the processors.