It’d be better if people knew what your “usual host of plugins and VSTi’s” were.
Since your question is “what would you choose”, and “you” is me, my answer is I’d choose a Ryzen 7 2700x based build with 16GB of 3200MHz memory minimum. I would do that because;
a) it’s sufficient processing power for my mixing needs now
b) it’s a good price/performance ratio
c) on that note it includes a cooler, and like you I already have a dedicated GPU
d) I hate Intel
e) 8 cores will be better in many cases other than DAW use, such as some video processing and multitasking
That said you are obviously not me, so…