How large is the hard drive to be backed up? a standard IDE CD writer is a good idea, but you will need a CD file system (available on aminet) and the makeCD software. All pretty easy, and straight forward. Or, if you have another IDE hard drive just lying around, that will work too.
If you are going to put the machine into use, just keep an eye eBay for a Zorro network card - they popo up every now and then.
Good luck!