When it comes to 400w or 450w it really depends on what you're running. For the vast majority of people, 400w is more than enough. Then, again if the 450w is only a few bucks more then I would probably go with that. Enermaxes and Antecs are both nice. I have a 350w Enermax Whipser PS running a system with the bays packed and a bunch of case fans. Check out my rig to see everything I'm running. As andalas mentioned, PC Power and Cooling power supplies are really good, but they'll cost you.