I think I've decided to go with the midwest guinea pig cage, but make the top from the cubes and then put a fleece liner in on top of the canvas one that comes with the setup.
It seems easier in terms of moving as I'm a student and it will be difficult to fit a large piece of coroplast in my car with everything else I have to bring back and fourth. And because I'll need to bring it to school with me and then bring it home for vacations and when I come home for the summer.
Thank you for the advice!!