When you take out the center console, there should be mounts you can screw the box into, once it's built.I have a 2k Dakota Club Cab, ive been thinking of Replacing the Center seat upfront with a custom Console, lol. im new to this, so. figured id ask. Plan to put a sub in the back of it if possible. and have my GPS (Small one), Sat Radio in it. Along with cupholders and a place to store a few small things.
The main thing is for me, going to be finding the best way to mount it where the seat was. and the best materials to use. and to prep/paint it.
I'd assume a combination of 3/4" thick MDF and Fiberglass will be your ticket.
Good luck! Should be a fun project.