I can only give you the following suggestions:
Don't buy a laptop if you want to do heavy gaming. Buy a good Tower-Case and live with it.
If you buy a 64 bit operative system, there's no need to go above the 4? 6? giga of rams, since they won't be able to use more.
Renounce the idea of using SSD hard disks immediately, they cost and are worthless in the greater wheel of things (that is gaming, if you want fast retrieval of system boot and so on, by all accounts, go for it, but it's costly and means little. Two Terabytes of normal or 256 gigabytes of SSD have the same price, to say)
Cooling, alway take care to get a good cooling system...
for Video cards, Dedicated memory first and foremost. That said the choice is usually either Nvidia or Ati.
Now with Nvidia, you can play far more easily at games like Unreal Tournament, Empire Earth three, and so on (they've got that physx thing attached to it) ATi can do the same, but it requires more effort on the video card, since it 'converts' something into something else (Can't recall for the love of myself what in what though)
Ati are seemingly cheaper and have the Crossfire option (Meaning you can buy two identical videocards, 'bundle' them together, and have a better experience)
For the operative system, once the architecture is 64 Bit...well, consider you could...'cut' off a large chunk of money if...say...AHOY!
*coughs*
Well, that's all.