24" mattress height is our default. Any other size will raise/lower the entire bed, not just the mattress. The headboard and footboard in relation to the mattresses stays the same.
Please let us know at time of order the thickness of the Mattress and Box Spring (if applicable).
The default support is for slats directly supporting the mattress"direct slats" option. Specificy if you use a box spring so we can design your bed to compensate for the box spring.
There is no clear advantage/disadvantage to using a box spring under the mattress.
Queen beds and larger have a center support with leg running down the middle on all support configurations.