Edit: Assuming you tried to boot from a FreeDOS CD, and it didn't work: You do not need a full-blown Bootcamp/Windows setup. You don't even need to run the Bootcamp wizard (however, a small FAT32 volume on the internal hard disk comes in handy in the process). All you need to do is install the Bootcamp package, which should install the firmware update during the next reboot. If you decide you do want to backup your original (4870) ROM, which is highly recommended (I'd have a fancy paperweight by now otherwise), you still don't need Windows - FreeDOS will do. In that case, run the Bootcamp wizard, let is shrink your hard disk by a couple of MBs, and simply don't insert a Windows CD when prompted to do so.
OK, this sounds totally reasonable. I'm all excited!
So one last question: any reason at all to go with the Sappire over the XFX/XXX?
Maury