I can say with 99% accuracy that the BIOS will only natively handle USB keyboards. Maybe mice but the BIOS itself doesn't use a mouse so it's hard to test that fact without resorting to a boot from and external CF disk.
But on the outside chance that they were brilliant enough to allow it, try one of those 120MB floptical drives in USB format or one of those USB ZIP drives. I can't imagine them using some proprietary solution.
Buy it, try it, return it... 'tis the season.