That's a USB flash drive? I don't think there are any SATA->USB converters, only USB->SATA. More likely to find a FW->USB converter. I think the MiniStack drive has this feature.
You *could* I guess boot into OS X for a file transfer at USB2.0 speeds, then reboot into OS 9 for the rest of your work. Just avert your eyes
Or indeed Linux. Heck, run MacOnLinux with Ubuntu PPC for the best of both worlds.
protocol7: sounds like you got a flaky card.