Use the Security Assist Wizard to create the Login pages, and use the Data Assist wizard to create the Search / Results pages.
Then use Framework builder plugins to add the Security assist / search functionality to your existing pages.
See the following tutorial for details:
http://www.webassist.com/tutorials/Getting-Started-with-SecurityAssist
http://www.webassist.com/tutorials/Getting-Started-Guide-with-DataAssist
http://www.webassist.com/tutorials/Getting-Started-with-Framework-Builder
for details on adding upload or download, see the following tutorial:
http://www.webassist.com/tutorials/Apply-file-upload-or-download