First of all, it's a fork. Secondly, have you tried contacting Fox (either through your LBS or directly) to see about getting your lowers replaced? Not talking trying to warranty it (unless that's a possible) but just paying them get new lowers. You might be surprised.

You're probably going to have a hard time finding used lowers; Fox forks are prized enough and expensive enough that people who have problem ones get them fixed rather than writing them off and parting them out.