I was just logging in to reply! When the page reloaded you post was already there lol. I was going to mention that I tried a heat pad side-mounted on a sterilite bin with my African Bullfrog, and while I haven't had a fire(yet), it simply doesn't heat the bin very well. That being said, I've used Sterilite bins a lot, and for large frogs and/or non-climbing frogs I've found bins are amazing. I use 90qt(20 gallons, roughly) bins for my Woodhouse's Toads, my African Bullfrog, and a smaller bin as a temporary tank for my Treefrogs.
Monster has the heating pretty much covered, a ceramic heater or a red heat bulb should work great, especially if you use metal screen for the top(some people say plastic window screen will melt from heat emitters and heat bulbs. I personally use plastic screen and haven't had any melting problems, but you can never be too careful.)
There's actually a sticky on modifying sterilite(or other brand) bins for use as terrariums somewhere. Came in real handy when I was trying to figure out what to use to attach the screen to the lid to cover the hole.
http://www.frogforum.net/showthread....arium-Vivarium
Also, the divider is a really good idea for Pacman frogs!