Browser Extension Required for Safari

I have already developed a browser extension for chrome and firefox but i would like to hire someone to do create the extension in Safari. The extension needs to display a browser button on the toolbar and to put a menu in the context menu for a page and a context menu for a link. In all cases the button and the menus open up the current page or link in another website. I have the same extension published for Opera 15 so a prospective developer could just download Opera and then my extension to see exactly what it is supposed to do.