Seems like a lot of information available. This might be a good place to start. This list is easy to read and follow. They link to company information. Silicon Invester - A master list of many companies.
Profiles also list competition.
May be a good source for developing company list in specialized areas. Only drawback, company contact person and address are not available. Using an Internet search engine can be helpful in locating companies who are on the Internet. When doing a word search, start with the correct full name of the company. This may return a few results.