Answer:
Very complicated since you cant give a laptop a new graphics card but possibly some new RAM. Look/ask a person at a local computer store and say where are the gaming laptops. Usually they cost like $1,000 but its for everything already put in there. The best website to do this from is compusa.com some laptops and even spare parts!
(optional idea) Heres my gaming story i thought about a gaming laptop it turns out they cost more than a desktop gaming so try to get some good stock computer. Mine was a stock HP Pavillion with 3 slots for graphics cards so that means future cards could work, any Nividia Card then do a Triple SLI. So i found a super saleat compusa.com i got a 8600GT for $80 compared to the $100-$160 i saw. Right there you save! Then i got some Kingston 16 GB RAM 2 cards 8 GB RAM each for $50 compared to the $80-$100 i saw. I needed RAM for my Supreme Commdander Forged Alliance (aka SupComFA) to run super battles of 1000+ units. Otherwise get RAM if you think you need to or you get a error message saying more RAM needed. No im not a geek i studied this for a while since it was the summer and i wanted to make my gaming computer better.