I finally broke down and built myself a permanent brooder box. I saw some plans and pics of them on here, and combined that with some of my own ideas, and some left-over lumber. I'm pretty happy with how it turned out. Everything is pretty self-explanatory. The box is 48"x 30"x 24" tall. The shallow tray (6th pic down) is a removable tray that sits in the bottom of the box. Although it'll be a two-person-job, it will hopefully facilitate much easier cleaning of the box (lift out, dump, lower back in and start fresh). I was going to put legs on it, or even set it up on a table, but it ended up being so big that I think it will be fine sitting on the floor in the garage.