Scott,
You should be just fine with what you have. That is a very large container and has the capacity to hold thousands and thousands of dubia. The makers of the UTHs have to say that you aren't suppose to attach it to plastic, but it is just fine to do that. I actually had to tape my UTH on because it wouldn't stick on its own. I would place the UTH on the bottom of one side and always have it turned on. Place your egg crates inside the bin on the heated side and stack them vertically. Put your food and water crystals on the other side. Cut out a large rectangle in the lid, about one-fourth the total size of the lid and attach alluminum screening to it using some silicone. Do not use the fiberglass screening (roaches can chew through this). Once your roaches are in there, put the lid on the bin with the screen portion over the "cool" side. Now just put it somewhere dark and try not to disturb it. Over time you will figure out how often you need to replace your food and water. For me, it's every Sunday. If you want to see some pictures, you can search the "Feeders" section. They are everywhere.
