that depends what are you planning to overclock?
and you could use a better PS just in case you want to add a new graphics card and this power supple is energy efficient and also the cables are removable so you only install the ones your using (this helps keep a good airflow in the system)
Ultra X3 ULT40312 850-Watt Power Supply - ATX, SATA-Ready, PCI-E Ready, Energy Efficient, Modular at TigerDirect.com