It even has wheels on one end so I'm going to make a handle in case we need to tow it along up a ramp or something.. It has handles as well for carrying but it'd kind of look like a giant cooler if being pulled!
I'm going to use the front part of a super pet cage that has the door in the lid so I can open a latch to give food/etc from the top, but won't have to take the entire lid off. For taking them out or cleaning the entire lid can easily be removed.
I don't know if I'll put a wire-grate in the shorter side ends or just drill more air holes. They might not enjoy having too much viewing-out and I wouldn't want them to be able to reach through and chew on anything they shouldn't!