Here are some choices:
Mesh PR600 £599 (but no fingerprint)
Evesham Voyager C550SR £699 (also, plus heavyish)
Dabs is good to be able to enter specific requirements, as i have done here for you:
Dabs choices
Overall though, this
Acer at £625 seems to have all of your requirements inc fingerprint scanning security, as well as weighing only 2Kg. That's my recommendation, although i havent used any of them personally.
Just for my peace of mind, are you someone who is generally familiar with the PC scene right now? Have you even considered stuff like a Macbook or the Asus Eee??