Is it possible to have a open cupboards on the top and doors at the bottom?

Most certainly, this is the beauty of the Werner system, by stacking the units to achieve the height required the user can select exactly what they require, its possible to have doors on the bottom 3 levels then an open section in the middle and different door again on the top.

What is the lead time for specials?

All the Werner cabinets can be modified to become specials and still remain on the standard leadtime.