Help on choosing a power supply

Hey guys, i was hoping that i could get some help on choosing an adequate power supply for a computer i'm building. This is my first build so i'm not too sure which one i should choose. My current components are:

1. Intel Core i7-2600 Sandy Bridge 3.4GHz Processor

http://www.newegg.com/Product/Product.aspx?Item=N82E168...

2. 3 Kingston HyperX 2GB sticks of RAM (6 GB total)

http://www.newegg.com/Product/Product.aspx?Item=N82E168...

3. Radeon HD 5450 512MB 64-bit DDR3 PCI Express Video Card

http://www.newegg.com/Product/Product.aspx?Item=N82E168...

4. ASUS CD/DVD Drive

http://www.tigerdirect.com/applications/SearchTools/ite...

5. 320GB 7200 RPM 8MB Cache SATA 3.0Gb/s Hard Drive

http://www.newegg.com/Product/Product.aspx?Item=N82E168...

Any help would be greatly appreciated.