I buy Dells for people and have had a couple myself.
recommending spec really is down to what you need to do with it.
If you don't need the graphics power try the middle option at £549
http://www1.euro.dell.com/uk/en/hom...px?refid=inspiron-1764&s=dhs&cs=ukdhs1&~ck=mn
Try ringing them for a haggle on delivery or a cheaper hardware upgrade.
Avoid the online warranty, rarely had a problem with adult owned laptops and they will probably ring you with a lot cheaper warranty package if you decide you want it.
do you need windows XP or will windows 7 be ok? do you need to run any old software/hardware that may not have 64 bit driver available?
apart from that I think you always pay a bit too much for a Sony product simply because of the name IMO.
Not sure about the esaver deal as I have never heard of them.
If you can wait for the overstock from easter to get advertised you may get better VFM next week from Dell.