Re: fiberglass box / pedestal seat bases
Cage Rattler,
I am sort of new to the process of fiberglass boat building, but I have been a cabinetmaker for some time. I have a similar idea for my boat, as I would like storage under my pedestal seats.
Couldn't you just build a box out of plywood, to whatever shape or configuration you are looking for, and then just wrap it in fiberglass and then tab it to the deck.
Another option would be to mount some angle iron/aluminum to the deck (everything sealed, of course) and then bolt your fiberglass wrapped box to the pieces of angle.
I'm not sure how much a box like the one you have pictured would cost new, but I would guess that it would be more than you would pay for some plywood and fiberglassing materials, and you would have to go with whatever features the company decided to design it to have. If you build your own, you could make the box under one seat a cooler, for instance, and the box under the other seat a storage for tackle trays.
Building a simple box is fairly easy, and wrapping the box in fiberglass and applying a gelcoat are probably all things you could tackle.
Another nice thing about building it yourself is that you could build it for your perfect seat height, based on the height of your pedestal mount.
Just thought I would chime in.
-Kevin