The latest supported customer release (5.7.5.0) actually includes this feature to allow you to filter your search results. See attached screen shot.
It uses SOLR facets to get facet information for the categories and manufacturers and so is very fast. The categories are sorted by popularity rather than presenting a category tree.
You should also take a look at our Intelligent Suggested Search feature (http://www.konakart.com/konakart/Welcome.do - Top Right Hand Corner) . This list is also sorted by popularity and for each product we store:
• The category name(s) of the product. i.e. Televisions
• The name of the product manufacturer. i.e. Sony
• The name of the product. i.e. Vaio
• The name of the product model. i.e. VPC-EB42FX
• The name of the category by manufacturer. i.e. Televisions by Sony, Televisions by Philips.
• The name of the manufacturer in a category. i.e. Sony in Televisons, Sony in Computers.
So if in our demo you type in "mi" you'll get, in order of popularity results like:
- microsoft
- mice by microsoft
- microsoft in keyboards