A search engine will be the best database in this circumstance. Your inquiry is specific enough that any firm meeting your criteria should be easily discovered through a combination of carefully selected keywords. Any firm not revealed either (1.) doesn't fit your criteria, or (2.) has no real understanding of online marketing. If they can't do it for themselves, what would make you think they can do it for you? Trust your search engine.
Having a significant number of fans as well as positive feedback and interaction from current consumers, prospective buyers viewing social media sites can be reassured that the product or service the business provides is trustworthy.