Have you tried Liberace? Or perhaps Elton John has some
(Seriously, if you can't find any then give one of these a try they're far more subtle than you'd expect)
http://cgi.ebay.co.uk/Watch-Band-SS-SPRING-Extender-for-Larger-Wrists-Free-Sh_W0QQitemZ140074454706QQihZ004QQcategoryZ98624QQtcZphotoQQcmdZViewItem