If pulling the HD out of the Firewire 800 box can't be done, I wouldn't be running digital video through a converter; I suspect it would be doing a re-encode and you'd lose a generation of quality.
If you have a PC desktop box, I'd buy a Firewire card, install it and use it to copy the firewire drive DV files onto another drive (internal or external). Then you'll have pristine, original DV files to work with when you get around to it.
Or find a mate who has a computer with a FW socket to do the transfer...