Hi there.
I am assuming that you want a Google Chrome extension with Firefox, right?
Then, you want when a user clicks on the extension icon, to have a button with a picture inside it, or next to it? What picture? When the button is clicked, you want a drop-down menu of websites? Can you elaborate on 'feely'? What does that mean? Do you want to have a multi-language extension? Right?
Are those websites hardcoded or should user insert them in some way?
Also, when do you plan to start the project and when is the deadline? Is the price negotiable?
Anyways, feel free to hit me up so we can talk more about this. I am very responsive. All the best