I have an Avid BB7 mechanical disc front brake with an Avid 185mm rotor. I assume this one on Ebay will work just fine? It's a slightly different looking design but that doesn't matter does it?

http://cgi.ebay.com/Avid-G2-Clean-Sw...QQcmdZViewItem



What about this one? It's only $8 and sais it's for a Juicy 7.

http://cgi.ebay.com/AVID-185MM-BRAKE...ayphotohosting

Thanks!