Customize search.php

I'd like to customize my search.php page. If you look here: http://www.etalentshowcase.com/search.php?search_mode=adv , you can see all the checkboxes on the page. I'd rather the page have just Actor, Band/Groups, etc as checkboxes. If you select Actor, then you get all members that selected Actor, with the option to search for members that selected Commercials, Stand-up Comedy, etc.

I basically want a nested search that hides the subcategories until the main category is searched.

Thanks,

Alan