Intel still is king in single core performance, but AMD is not far behind. But Intel has production shortages right now, so their premium priced products are even more premium. If you don't need 8 cores, get one with less. Simple as that. AMD is looking very competitive in price/performance across the complete spectrum now.
Personally I would recommended getting an AMD CPU with fast RAM. The RAM speed spec for AMD Ryzen 2nd gen is 2933MHz, so any slower (2666MHz) will run below factory speeds. Any board should support factory speeds. If not, return it.
You do have much more faster memory like 3200, 3600, etc. But basically you're overclocking at that point. If you want a stable system, don't touch any OC feature.
The necessity of 16GB or 32GB is a personal thing. 5 years ago, I built an i5 system with 16GB DDR3 (costed me 100 euro's back then). 16GB serves me well in both my Linux workstation (which I use to run 2 Windows VMs + Jetbrains IDEs at the same time) and my Windows desktop (CAD + entertainment). , With recent DDR4 shortages the 16GB DDR4 prices haven't even settled down to that level.
Unused RAM won't hurt anything, so if you can afford sure go ahead..
If fast RAM is at the cost of a SSD (NVME if possible), then