Well, I'm not sure any of those would be the best choices. The Sony is incredibly expensive especially considering they are giving you an incredibly under powered processor. The XPS will by far give you the most power, but again it's at a cost. The Latitude is similar to the Sony, but it is cheaper and has a slightly better processor. Now re-reading your post I see that he doesn't need a ton of power. If you are willing to spend the money on either the Sony or the XPS, the XPS would be my choice. It is rated as one of the thinest 13'' laptops and comes with a full powered CPU.
Others to consider are Dell's Vostro and Inspiron lineup and also HP's DV2500. Of those three, the HP is the nicest looking IMO.
Check out the Dell Inspiran, 1500 series, I think the 15'4" is a nice size, the 17" is kind of big if he'll be taking it out much. You can get a fully equipped AMD, i.e., 160GB hdd, 2 GB RAM, and DVD burner, for $800 or less. Plus you get you're choice of 8 colors so he could get the sexist color but not sure what that is. At least for me women and cars are sexy, laptops really not.
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