Chrome and Internet Explorer Intercepter

I am looking for someone to develop a library that can inject in popular browsers such as Internet Explorer and Google Chrome and intercept POST requests (ssl and http) and modify a webpage content (either http or ssl). Also the author will need to write a small description on how he found the functions needed to intercept in google [login to view URL] software should run on the latest chrome version at the time and on IE- 8 - 9 -10. If the author can supply source for firefox additional funds will be added. Thank you.