Vertical would be my preference.

Vertical is standard, horizontal is more MCM

Vertical will be less expensive. But both choices are very very expensive. They require a true custom master who builds, finishes, and installs, frameless cabinets almost exclusively.

Vertical is easier and less expensive, I prefer it. But make sure it works with your  floors - it's better for the grain of the floor and the cabinets to have difference in direction. If you want the room to look wider, go horizontal. If you want the room to look taller, go vertical. I think looks more elegant to visibly elongate the height of a kitchen as much as possible.