these are supposed to be good and quiet
Looks like a good build.
Only thing I'd say is maybe push out an extra £20 for the quad core:
Have you conisdered the new Athlon II x4? Quad core for £10 less. Would be better for video encoding and photoshop etc.
Is a Phenom II x4 without L3 cache. Nice.
I'd get the cheapest BeQuiet one on at the minute (PSU). Case i'd change to something like an NZXT Beta, and put the money towards something else. RAM i'd go for the 'blue' ripjaw or the £60 OCZ one. Cooler would be TX-3 probably and MX-3.
Only thing I'm concerned about is that the PSU is only 500W. I do want to go with Zalman though as the sound of silience is important. Reckon a 500W will cover an upgrade to a 4870?
500W will deal with a 4870, and a decent brand 500W will do a 4890 without issues too.
Those Zalman coolers arent quiet unless theyre run on the lowest settings, much louder than an OCZ PSU anyway. So theyre pretty much useless if you want any kind of quiet overclock.