The two main categories I concentrate on K and WHIP. Basically what this does is produce pitchers who miss bats, don't walk much, and give up few hits. With that scenario, ERA and wins follow suit. As you have probably read, ERA tends to fluctuate and do NOT chase wins. You can mitigate this by then placing emphasis on the IP category. The 5 SP/ 4 RP requirement will probably keep IP close. But by focusing on SPs that go deeper in games, it is more likely that they will win (with higher IP as a bonus). I go cheap as possible with Saves, as it is more job security than nastiest numbers. With Holds, I'd take an elite option that will rack up the Holds and could potentially move into closer role if someone gets hurt, just don't spend too much here.
Hope that helps a little.