Channel Well Technology do. If you have a peek through the vent at the back you will see green, this is green tape wrapped around the transformers, and this is a hallmark of CWT. You could also read a review on it from jonnyguru, hardwaresecrets, oc3d.net, etc.
Culumusjames, do you really need a soundcard? My advice is that unless you work with audio on a more than casual basis, or unless you are an audiophile, then the quality of onboard sound is reasonable and plenty are happy with using it, you can also pretty easily install it later if you find that you do need it. Perhaps you could make do without it for a period after buying a power supply that is adequate for your needs.
Also there are some, probably quite rare PSUs that are nearly inaudible throughout their power range. Nexus is a brand who I am aware that this is true of and from the reviews I've read they are all reliable and high quality, maybe not the best, but nothing to shy away from.
I know where you can get the Corsair CX 400 from, for £32, unfortunately I can't provide a link.