FINVIZ.com offers an extremely advanced free stock screener you can access at no cost once you register for a free account. You can even save custom screens, portfolios of stocks you would like to keep an eye on, etc. Very nice!
I’m always looking to purchase a new company. Everyday I run multiple stock screeners that do my heavy lifting. These screeners data mine the indexes looking for certain metrics that I program into them. This gives me a starting point.