I need to build a 'Member Directory' listing companies

I need to build a 'Member Directory' listing companies which will be listed by category. These 'companies' will be added manually (not linked to WP users).
In a way it needs to be similar to a 'portfolio' style section, so users can select a category, then be presented with a list of companies who match that category.
Do you have any plugins which could achieve this easily?