If it is a straight-forward wiring setup, you can find Svideo-to-2-RCA adapter cables on the market. This would give you the 3 RCAs of component video for the connection, probably cheaper than a Bose cable. Unless there is some other bizarreness Bose does, perhaps switching the signal and ground/shield lines on the Svideo output, but it doesn't seem likely.

You'd have to figure out which cable is which (matching the green, blue, red for component), though.