I really doubt you'll have any trouble with either Kingsnakes or Ball Pythons in any commercial rack. Now, if you plan to keep hatchling Mountain, Grey Banded mexicana or other small Lampropeltis spp. in lidless racks then I would look into it more carefully.
The only issue I can think of is if you're buying a rack built around the new Sterilite boxes with the built in lid-clips. I believe these clips need to be removed and leave a small gap at the long ends of the tubs. I have heard speculation that this will create security issues. I have not seen it for myself other than a picture posted on another forum so take it for what it is worth.
And of course this would apply to any rack using the Sterilite boxes, not just AP's.
As far as clips to hold the boxes in, these are really not necessary. If you need it for your peace of mind you can probably use binder clips or have some sort of recessed pin system fabricated.