ok next update... the quote is £667 for above spec, as changed.
I have the option of saving £30 if I go for an Asus P5GCMX Motherboard instead of the Asus P5K/VM Intel G33 LGA775 .... ??
I have built my own PC before but that was before I owned a toddler I'm a bugger for using lots of apps at the same time and wasting resources so I think from what I've read that the quad would be best for this?