for gaming a similarly equipped Amd will rip intel from top to bottom. But unfortunately not many systems are available.
options for you are
acer ferrari 4005-4006
dell xps170 (17inch)
Dell E1705 (17inch with dual core)
toshiba qosmio for multimedia powerhouse
alienware, hypersonic, sager(including pctorque),voodoopc etc are all boutique anufacturers. I wouldnt recommend buying a high-end system from them. A high-end system is bound to crash once in 3-4 months and getting service outside US is a problem.
but if you still want to buy one then look at
www.alienware.com www.pctorque.com
The 9750 from pctorque and similar model from alienware are the most powerful gamers you will find on the globe right now. They come with dual core amd's and amd fx's along with nvidia 7800. But then the weight is also clost to 6-7kgs.