it will be a looooong way to go yet before on can pick & choose laptop parts - this area is still too lucrative for the laptop manufacturers and their resellers to allow it to happen.
many co like, sager, msi, alienware (to name a few) offer user the possibility to "choose" within their offer of the day/month/year to upgrade/customize his/her laptop of "choice"
laptop gpu is the hardest (may be impossible) to get, unless u prepare to buy it in quantity, of 100 per example, just to start. best thing is salvaging it from "pick-a-part" user groups/forums
next come the issue of mobo bios/chipset, may be u got lucky to have a good mobo but then, the bios is being held back for next "improved" model, which turns out many times just a simple cpu upgrade - still, it would come in a form of "different" bios version.
back to ur query, just a simple asking about a specific graphic card, i would google/yahoo/msn/ask-jeeve ... for this graphic/laptop and try to narrow it down.
(when u r brave enough to travel)http://www.carillondirect.com/clnweb...jsp?country=UK
on the lighter side:
2 fans met up at the corner bar. "u know, my wife is divorcing me for spending too much time watching/following the world cup" - "well it is a real tragedy!" exclaimed his buddy- "I know, i 'll be missing her, for sure, in the coming month."