our gaming notebooks which are pretty much the most powerful notebooks that we offer are the G series. currently G53 or G73. both feature a core i7 740, and GTX460m. these are pretty big notebooks tho, im not sure if you need something mobile.
asus does not offer customization to the user but there are some etailers out there that will customize it for you, check out the etailers here:
http://www.asusrog.com/G73.htmlasus notebooks are designed for easy upgrades for your harddrive, if you want a harddrive and ssd, its something you can easily do yourself. ram is also very easy to upgrade if needed. theoretically you can upgrade or downgrade the cpu as well. but this could void warranty. graphics card is a mxm module so it can be swapped out, but only problem is the heatsink assembly may not be able to fit the next gen cards, so im not sure if this upgrade is realistic. but it goes to show what we are capable of doing.