You could save £40... still, it's your choice.
That case is very expensive, you could get the same for less than half that.
I'd say two 4890s in crossfire (or even 4870s... or a 4870x2). Both of which out perform the 285. Not sure about motherboards that support crossfire and an i7 though. PSU is slightly overkill, you could probably make do with 200W less than that.
You sure you need the Titanium? You're not going to be able to tell that much of a difference over the lower end of the scale, which is only like £30.
Definitely use a PCI wireless card, so much faster and more convenient.
See if you can find some 4-Pin case fans as opposed to three, 4 pin with TWM (or something like that) automatically adjusts the fan speed depending on current CPU load.
Wouldn't you want a DVD drive that supports LightScribe or LabelFlash? They're not that much more expensive and it's really convenient.
You might want a better CPU cooler. Hell, for that price i would cut back on a few things (case etc, that i've already mentioned) and rig up a water cooling loop.
Hope that helps
