Putting js in the bottom is not really the thing that I would start with.
It's better to do first things that affect users of your site, such as combining js files, you currently have 27 different js files (plus css), and minifying them if possible. This will make your site load much quicker. If you can enable gzip conmpression on your server.
After that you need to setup expire headers for js/css, since I don't think you modify them often.
This will bump your load speed and your YSlow grade.