Depends on your budget.
If you can afford it go for ocz, xigmatec, xfx, corsair, you'll only need 450 500watt if you get one of these.
If not get a high wattage budget one, but with that you'll have to check the 12v amp rating and you'll need something like a 700 watt unit just to get around the 450-500 watt performance that you would from a decent unit.
Cit,winpower,evo labs,alpine, arctic are some of the budget makes.
Oh, if you do go budget, get a unit with a single 12v rail, dual 12v rail on budget psu is fail, trust me, I've been a victim of it!