I could do this for you but it you seem to be doing great so far with the site. The site looks great! I thought it would be better if you learned how to make dropdown menus.
The easiest way to add to this would be to use Superfish (http://users.tpg.com.au/j_birch/plugins/superfish/#getting-started).
All you would need to do is setup add to the menu the submenu list, add suckerfish.js, and then call superfish() on the containing ul element. Follow the getting started and you should get it. It is much better to just learn rather than just pay someone for something so simple 
Let me know if you need any help or really want me to implement this for you still.
Kyle King