What are big companies looking for?

Hey guys I've bought a 800 series prep course book along with a series of videos online to watch for the Comptia A+. Is 800 series still relevant compared to the newer 900? Do big companies higher for both or are they that similar? As someone trying to go far into the world of computer techs, what is the best suited at the moment and what other certificates besides the A+ should I achieve for?