Welcome to Polycount paulsvoboda
As Ott said the best way to get employed is to be a specialist of some sort. My personal opinion is that you should follow whatever interests you the most because it will give you that much more motivation to get things done and study harder. It doesn't hurt to study other aspects of game art as this will broaden your knowlege, but you should focus your portfolio on one area of expertise. Also be sure to post up work in the Pimping and Previews sub forum here on Polycount for critiques and advice.