Which PSU?

[VapourTrail]

Looking for advice on which PSU to look for for my new rig which will consist of ...

E6400 Conroe
Asus P5B Deluxe
GeForce 7900 GS
2 x 1GB RAM
2 x HDDs, 1 x DVD, 1 x multi-card reader
Grateful for advice on a decent PSU to go for. Not sure if I should look for a 600W or bigger PSU. Would also like one that is fairly silent and does not cost the earth (possibly around the £30 mark).

 

[VapourTrail]

Fill it in urself if u dont believe me : http://www.extreme.outervision.com/PSUEngine

Thanks for the link. Filled it in (including USB, fans etc) and it looks like I would need 356W. However, any overclocking of the CPU pushes the requirement up towards the 400W mark. Adding a dedicated sound card and a PCI card pushes it over 400W. Therefore, I presume I should be looking at one that delivers 400 - 500 W which gives me scope for future addition of a extra drives etc.