Would you good people kindly check this for me please 
i5 750 OEM
Gigabyte P55-UD3
G Skill Ripjaw 1600mhz DDR3 8-8-8-24
HD 4850
Samsung F3 1TB HDD
Coolermaster 335 + 460w PSU
Is that PSU wattage enough? might add a 2nd GPU at some point and will be running a 2nd HDD. Also if I am getting the OEM CPU then do I need to buy anything extra ie fan/heatsink??
Many thanks

i5 750 OEM
Gigabyte P55-UD3
G Skill Ripjaw 1600mhz DDR3 8-8-8-24
HD 4850
Samsung F3 1TB HDD
Coolermaster 335 + 460w PSU
Is that PSU wattage enough? might add a 2nd GPU at some point and will be running a 2nd HDD. Also if I am getting the OEM CPU then do I need to buy anything extra ie fan/heatsink??
Many thanks