FTPS in IIS 7.5 is cool. Do you know how to configure it?
Check this 4 part tutorial...
http://www.dotnetscraps.com/dotnetscraps/post/Did-you-know-Configure-Client-Certificate-Mapping-in-FTP-75-Part-1.aspx
http://www.dotnetscraps.com/dotnetscraps/post/Did-you-know-Configure-Client-Certificate-Mapping-in-FTP-7-FTP-75-Part-2.aspx
http://www.dotnetscraps.com/dotnetscraps/post/Did-you-know-Configure-Client-Certificate-Mapping-in-FTP-7-FTP-75-Part-3.aspx
http://www.dotnetscraps.com/dotnetscraps/post/Did-you-know-Configure-Client-Certificate-Mapping-in-FTP-7-FTP-75-Part-4.aspx
Hope this helps, Rahul