2.5" External enclosure with FireWire 800?

I just upgraded my MBP's HDD to a 640GB and now I'd like to use the old 250GB HDD for backups and extra storage. I'm looking for a reasonably priced external enclosure that uses FireWire, preferably 800 but 400 would work as well.

If 400 is the only reasonable option, what is a good 800-400 cable that I can use?

Thanks

OWC has what you need External Hard Drive Enclosure Kits for IDE, ATA, SATA, Optical Drives