Thank you so much @Oussebon
1) I was not aware of Zen 2 at all, up to speed now, so I can definitely defer for a month or so if it is likely to give me a performance boost or a cheaper current Ryzen.
2) thanks for checking on the motherboard, I hadn't checked but had 'presumed' it had USB C, I...
FYI based on various reviews and the pricing here, I think I will go with the the Corsair 680X.
The Corsair 680X here is priced at £149 (≈$194), only £20 (≈$26) above the Corsair Obsidian 750D at £129 (≈$168) a 5 year or so design that, as @Oussebon and @SpyderTracks suggest is at greater risk...
RAM : Work too, dozens and dozens of webpages, and standard office apps plus a virtualized soft for product management and monitoring. I have 16GB now and it gets chewed up.
Monitor: 4k large beast, between 34" and 42" like the large LG or similar sized curved Philips. Both only 60Hz but I...
I've never had a high end gaming pc but I think I am ready. Originally I specced a Corsair Obsidian 750d case and an RTX 2070 but it has crept up based on suggestions and discussions and self diagnosis over the web! Any suggestions or improvements?
Case
CORSAIR CRYSTAL SERIES 680X RGB GAMING...
aha but that is almost 6 years old!
I like the lights and seeing the grand or so I might drop on a graphics card. It might be the drink (3 x IPAs) talking but I might be upgrading to the 2080Ti. All to play for. Will decide in a calmer moment.
Night night folks and thank you for the input...
Perhaps this one :
Corsair Crystal Series 680X RGB
https://www.corsair.com/uk/en/Categories/Products/Cases/Crystal-Series-680X-RGB-High-Airflow-Tempered-Glass-ATX-Smart-Case/p/CC-9011169-WW
All good points. I will see what else PCS have in their catalogue that would replace it but keep the size, airflow etc present but add the USB C which is potentially of benefit.