Can you advise me on a computer I'd like to buy?

For most people that will be more than enough power unless you want to play the latest games. Sony laptops are very good. I always advise not to buy a laptop unless you need the portability or don't have the space, they are expensive to fix if you get a problem and you will get alot more for your money witha desktop. Try to get one with XP not VISTA as it is still going throught the usual windows problems with a new version.