Wax,
Sorry I don't have any pics of my ferment box, but, I'll try to describe it as best I can. During the last round of council pickups I was lucky enough to pickup 2 veneer boardroom tables with solid wide legs (600mm x 800mm) (4 legs in total). This was used to build the box which hold four 30l carboys. 1 leg each for the bottom, top and both sides. Part of one of the table tops I used for the back of the box and I built a light weight removable panel for the front. Inside, I used some old MDF to create a small box (to contain either the light globe or PET bottles of frozen water) off to one side and cut a panel access in the side of the ferment box so I could get in to change frozen water bottles without exposing the fermenting beer to the warmish temp outside. At this point I realised the ferment box was bloody heavy without any fermenting beer in it, so I decided to visit a couple of "Fresh Food People" and abscond with some trolly wheels that I bolted onto the bottom. I got some 3" styrofoam to insulate the top and bottom some 15mm esky insulation (from Clark Rubber) to insulate the sides and front access panel. During the council pickups I also gutted several 286 PCs for the fans and 12v adaptors and a crappy old lamp. I bought from Jaycar a Thermostat which controls the light to turn on and off as well as a digital thermometer that I mounted outside so that I could see what the temp was inside the box when it was closed up. I was originally planning to put a hinged door on the front, but decided just to have an access panel that is held in place by bungy snaps (these can be found at any ship's chandlers). During the first winter of its life it has kept my ales at a constant 18 degress C (+ or - 1 degree). I've yet to see how well it performs in the summer.