What kind of space limitations do you have? The overall size affects shipping and sub/port placement options. Also the vehicle in which they will be installed will affect tuning and placement as well.
All of those affect the shipping as the overall size determines the shipping cost(not weight).
I would like to know your maximum usable height, width, and depth. As that would help with the design as would answers to the rest of the questions in the link I gave you.
I'm sure we can figure something out weather it is a design or enclosure build.