School Laptop

I have $3k comming from a research grant to buy a laptop and upgrade my desktop. The more I spend on the laptop the less I have fore acessories and upgrades for the desktop, but I'd like to get something fairly decent as the desktop probably only needs a processor and video card. I'd also like to pick up a 22" monitor and docking station for the laptop which will go in my office.

characteristics in order of importance are:
Portability
Battery Life
Power/graphics (i'd like to be able to do some light gaming)
Dockability

I've been considering all of these laptops, but i'm open to other suggestions, I'm thinking 13-14" would be best

Sony SZ series-slick but expensive and expensive accessories
Lenovo Thinkpad - klunky looking
Dell Lattitude 630 - bigger/heavier than the rest
Dell xps 1330 - no docking