I'm sure you can find a low profile platform bed, since you prefer a modern style.

Get a bed with a low profile hedboard and an adjustable mattress or some top down blinds on those windows

Is there a way to put the bed on the opposite wall, so you can lay in bed and look out the window at the beautiful view? Anyway, assuming you keep the bed in front of the window and want a low headboard, you might have better luck finding an older headboard (garage sale, Habitat for Humanity ReStore, flea market...). It does seem like new headboards are almost all super high and overwhelming, but older ones are scaled more reasonably.

Second the suggestion fro Barnes to look at a platform bed. And you don't need a headboard. Just use pillows and European Shams.