So I decided to make my own incubator this year, I simply bought a 120qt cooler at walmart and placed 3ft of 11" flexwatt on the bottom and taped it down with aluminum foil tape, I then covered the bottom with water bottles to keep the temps from fluctuating too much and added 2 fans (one blowing towards the heat tape and one blowing away from it, both are being help up off of the heat tape by bottle caps to allow them to function properly) and covered it all with a cut to fit egg-crate light diffuser, after it's all said and done I spent about $140 and can fit 8 6qt egg boxes in there. I placed one thermometer probe in the bottom right egg box and one in the top left egg box, after a few hours of running it connected to my Helix thermostat set at 89 the temps in the egg boxes are 89.1 on one end and 89.4 on the other.
Here are some pics of the finished product.
http://i239.photobucket.com/albums/f...z/IMG_0320.jpg
http://i239.photobucket.com/albums/f...z/IMG_0321.jpg
http://i239.photobucket.com/albums/f...z/IMG_0325.jpg
http://i239.photobucket.com/albums/f...z/IMG_0324.jpg