It really depends on what you’re most comfortable with; when you go for such a custom option most of the design decisions are about personal preferences.
I suggest you draw out some layouts on a piece of paper, adjust them until you feel happy and then plan out how you want the keymap to look. When you’re happy, look for a layout that fits what you want or build your own on KiCAD.
I bought a kyria from Splitkb, and I’ve been very happy with the design. If I needed another keyboard, it would probably be a very similar layout, but have slightly fewer keys, be low-profile and no oleds.
Not saying windows compatibility isn’t extremely important, but based on Windows on Arm’s track record, collaboration with Microsoft on this project specifically seems like more of a millstone than a windfall.