If you're just looking for white companions, here's what you do: Get on your cleric. Go to the Grand Emporium. Buy the Man at Arms and the Cleric. Go to the AH, get cheap level 60 purples (or blues if you have to) for the first 2 slots of each companion's equipment. Mail all of this to yourself. Make your wizard. Finish the tutorial. Get that care package out of the mail. Be overpowered for a VERY VERY long time.
As you're ranking up your companions, you can cycle them. Gotta send your Man-At-Arms out to level up for half an hour? Do that, and summon your cleric while you wait.
Man at arms was occasionally nice to have in the early game. Cleric is probably better, though, pretty much regardless of class. I find that enemies charge me no matter what.