I also was thinking of using sheet rock, metal, or osb. With osb you can attach brackets, hangers, ect very easily. It is more durable than sheet rock and doesn't dent like the metal panel liner will if you bump it. If you do use osb make sure to prime it with a oil based primer first. The glue in the osb will bleed through a latex primer. I tried the latex at first and it just didn't cover well at all.