If you want style and/or cable management, buy a high-quality modular power supply
http://www.frozencpu.com/cat/l3/g11/...ml?o=price_asc .
If you want my personal recommendation, buy a 400w+ Enermax PSU. I've been running my 350w Enermax NoiseTaker PSU for..drum roll: 4 years. My brother has been using his 410w NoiseTaker Enermax for 4 years as well, except he's had 5 (five) internal hard drives and an Athlon 64 and GeForce 6. Enermax makes incredible power supples that are extremely quiet and powerful.
http://www.newegg.com/Product/Produc...82E16817194009
http://www.newegg.com/Product/Produc...82E16817194003
BTW 400w is plenty of watts for a high-quality power supply but since you have a good budget I posted the ones closer to 500w.