Customization of osCommerce/search by category

I have built an osCommerce site for a client who sells school uniforms. Everything is ready to go, except the client wants to make sure that visitors CANNOT see all the school names he provides uniforms to. I have hidden all school names (i.e., categories) so now the visitor must be able to 1) enter his school name in a text box and submit it 2) have that school's categories and products show up to choose from 3) (if possible) be able to choose from two schools which have similar names (in case they enter the name incorrectly--e.g., Bellarmine Jefferson High School and St. Robert Bellarmine Elementary)