Inside mine I have a 14 gallon tank, an Optima battery, two folding chairs, some tools, a couple bottles of Mother's wax, rags, a plastic tarp, and there is still room for a heavy coat or a couple of hoodies, and all the damn flyers that you get at the car show. For pics, click on "409T", then "public profile" and then "photo gallery".
The sport deck is a bolt on item, so there really wasn't any body work other than the usual sanding before paint.
Jeff