Need help choosing laptop

i am going to get a laptop fairly soon and i want to be able to play unreal tournament 3 and half life 2/team fortress 2 on it. my parents have a $2000 CAN from their work they will let me use but i can't use it to build a computer, so i was thinking of using that and puting another $400 CAN or so of my moneyfor a dell XPS and upgrading the graphics card when the games i want come out. i was also wondering1. is it easy to upgrade a laptop (mainly the graphics card) and do i need a special kind of graphics card for laptops2. should i select a better graphics card on dells site, or just select the stock one and wait for a better one to come out and upgrade (there is no games i am buying before the ones i mentioned above)3. is windows vista ok and if so which version should i go withthat should be about it, heres a link to the one i was thinking of getting (it costs more after i get the options i want)http://www1.ca.dell.com/content/products/productdetails.aspx/xpsnb_m1330?c=ca%26cs=cadhs1%26l=en%26s=dhsNeed help choosing laptop
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