Chrome Extension similar to Minbox for Gmail. (OAuth and API experience a must)

Hello, You must be very familiar with OAuth and API's to do this job. We are a cloud storage provider and we are looking to have a chrome extension developed similar to Minbox for Gmail: [login to view URL] This extension will allow our users to use their account on our service when sending large files via email. We are only looking to replicate the email part of this extension only. So: a) Our extension's attach Icon to be added next to all attach buttons in gmail. b) User clicks attach button, browses to his files and file starts uploading in the message, once its done the link url gets pasted into the email message.