What kind of psu i should use for my pc

[lp150189]

i'm going to build a pc but i don't know how to chose a psu for my computer. the system that i plan to choose is
• GIGABYTE GA-EP45-UD3R ATX Intel Motherboard - Retail
• Intel Core 2 Duo E8400 3.0GHz LGA 775 65W Dual-Core Processor - Retail
• EVGA 512-P3-N871-AR GeForce 9800 GTX+ 512MB 256-bit GDDR3 PCI Express 2.0 x16 HDCP Ready SLI Supported Video Card - Retail
• CORSAIR 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 1066 (PC2 8500) Dual Channel Kit Desktop Memory - Retail

can you recommend for me some good psu. is that better or okay if you use a higher watt psu that your system needs. for example: my system just need a 500W psu but is that better if i use 750 W psu. I just wonder. thank you guys for answering my question

 

[spillicus]

Been very happy with a Zalman one. I can't hear it from 4 feet away, and it's been stable.
I did have one die on me though, but they honored the warranty without any trouble and sent a new one right out, so I'd still recommend it.