List the specs of your system - first let's make sure that a 400 watt psu will indeed be enough.
If you are planning to upgrade other parts soon, tell us what you will be getting so you can buy a power supply with enough watts for your future configuration.
I'm not sure how much power you would need but I have found that Antec power supply's with Low Noise technology are very reliable and quiet. For that I highly recommend any Antec power supply.