Designing Widget Dropdown

The concept is still similar, you just have one main “menu” item. Each category is a sub-menu item. You’re still navigating to pages after all. You’ll need to lose the standard form element and build similar functionality. You may be best off looking for a jQuery solution to do the basic functionality. Then it’s mostly a matter of CSS to get it looking right. While you could contain this all in a widget, you’ll have an easier time putting it directly in your sidebar template. You could always “wigetize” it later.

And for category fonts, you will use the @font-face CSS rule. Lots of compatible downloadable fonts from Google Web Fonts.