I would recommend a Seasonic-built unit like this one: http://www.newegg.com/Product/Product.aspx?Item=N82E16817151096
It is a little more powerful than you need, but should handle any upgrades you're likely to add.
For the price, it's hard to beat. The Corsair "Builder" units are made by CWT, not Seasonic, using some inferior Samxon capacitors known for early failure. They aren't terrible PSUs, but with much better ones available, why bother?
If you want something cheaper, get this Antec VP-450: http://www.newegg.com/Product/Product.aspx?Item=N82E16817371045
which, despite the little voltage switch, is actually a modern, efficient design. It was built by FSP.