[kaigan]

From my own experience and the Higher Intellect wiki's list, the Belkin F5U220 is your best bet for a USB card on the Chimera machines. I've used them in my deskside Tezro, my O350, and also my Altix systems with good success. They're fairly inexpensive on eBay.

For other options, there's also the Belkin N10117 (which includes Firewire), but I think my results were a little mixed with it. Finally, the Higher Intellect wiki mentions the Adaptec AUA 3020 Rev B (and specifically the Rev B - Rev A caused a Fuel to fail to boot).