G`day Guys n Girls

I`m having a dung hard time deciding weather to but this lapy : http://www.ebay.com/itm/ws/eBayISAPI...m=140613860173

ASUS G74SX-DH73-3D

Or

Wait the next tide out and build another beast based on either the x79 or 990fx chipsets. I will really only be gaming on this system and I do attend a lan party (Nerd Wars) Once a month; But I do demand that all my games (mostly singleplayers) run smooth as silk or as close as possible with all eye candy turned up. I know this system will meet my demands now and into the medium term future but ahh....

Questions : Any input would be better than none so in your opinions do you think this lapy will last me a couple years on the gaming front? If you could buy this or splash a bit more for an intel 900 series based system what would you buy?