Dell Inspiron 9300 vs. Dell XPS M170

[bkholdem]

I'd appreciate advice/input with respect to these 2 machines. I will be buying a new laptop. I only use 1 computer and since I have used a laptop I'd hate to go back to a desktop. I will use it almost exclusively for web brousing and playing poker. I am interested in these 2 due to the screen resolution.

If there are other laptops with 1600x1200 I should consider that would be great. Is there any advantage to me getting the more expensive machine given my use for the computer? I will also possibly be intested in getting a 21" monitor to go with it, also with the 1600x1200. does this change things or are there other considerations since I might do this? Can I just plug/unplug the second monitor to use only the laptop without complications with set up/etc?