Good question! There are a couple of considerations to consider: 1) Local building codes may push fixtures higher to protect you from bumping into fixtures. 2) Light output/distribution of the fixtures and your eye height (will it cause more or less glare depending on how high you hang it?) and 3) architectural aesthetics- IE, do they align with patterns in the doors or windows? Typically we recommend somewhere around 6' to the center of the fixture, which would mean yours begin at approximately 5'3" and rise to 6'9". Depending on the style, it might look better to hang the top at 7', this the bottom would be 5'6" above the floor. If you have a transom, like the sketch above, you may be able to cheat higher. And, at the literal end of the day, it is important for it to feel good to you. :)

Thanks for your quick response, your posts are so helpful!