You may be able to snatch one at CPFMarketplace but why would you do that... call Surefire or send them an email, be polite, explain everything and they WILL help you, they have an outstanding customer service...
Surefires customer service is excellent. They are sending me a replacement A2 tailcap (a complicated and expensive part!) just because a tiny part of mine broke and I decided to email them about it.
I'm fairly sure that Surefire clips are actually engineered to break/bend when there's too much tension on them, so they should send you a replacement without any difficulty at all.