there is no reason not to get a motherboard with the Z390...and if you haven't gotten the 8700K yet, get the 9700K instead. 8 cores beats 6 cores / 12 threads by almost 15% and should have no issues hitting 5ghz if you want.
that said, anything with the Z390 will let you overclock (CPU willing), so get what board you like the looks of and has the features you need/want.
or, if you haven't bought anything yet, perhaps wait for Zen 2 coming in July and see if AMD finally beats Intel once more. h34r:
Hardware Canucks is focused in-depth reviews of the the latest graphics cards, CPUs, storage, smartphones, notebooks and gaming peripherals. Join us as we unbox, review and benchmark the best computer hardware on the market.