Normal
I would do a simple thing, get 9900k and just limit its TDP to 100-125W and it should be fine. Same goes for all other cpu's more or less, you can always to that and you won't loose any gaming performance. I wouldn't bother with flex psu, even if you could fit it they are really loud. It might be possible but it would be very tight, I wouldn't even consider that option tbh.
