New Laptop Needed

My current laptop (Asus) is near death (for example the 7 and 8 keys no longer work, requiring me to open up excel and type in =3+4 everytime I need a 7) so despite it being only 2.5 years old I am about to buy a new one.

I want something which has the following:

* Light (as I travel most weeks with it)
* Grunty (I generally have a dozen+ windows open at a time and my work involves database files ranging from 10 MB to 1 GB) – so a fast chip and at least 1 GB RAM.
* Long battery life
* Good wireless
* Windows not Mac (sadly)

A few people have suggested a Vaio, and I am tossing up between a VGNSZ28GPC or a VGNTX37GPB. The former has a dual processor, 20 GB more storage (but I have an external 200GB HD) and a built in webcam. The latter though is smaller (11.1″ vs 13.3″) and lighter (1.25 kg vs 1.69 kg) and longer battery life (9.5 hrs vs 7 hrs). They both cost $4K.

Any recommendations as to which of the two I should go with, or other models with similiar functionality? (links would be useful) Price is a factor, but not the main factor. Oh yeah and I also want something that will last longer than 2.5 years!