I can do it for you ;) We at Codware work all day with CSS, MSSQL/MySQL, PHP and JavaScript.
I'm experienced with databases, javascript and chrome extensions.
I understood what you want your extension to do... but i couldn't get it when you said:
"When a user visits the link, the user information stored locally should be exchanged to the currently visited website."
What kinda of exchange is that?
Please note that this bid has a initial milestone request. I'll not start working before its released (you can check our profile to see the comments of our loyal clients). ;)