Lol if you have enough money to buy and Alienware product, you should have enough money to build a high-end gaming computer as well as a 1440p display and other peripherals.
If you can't be arsed building it, retailers can assemble it for you at a cost, hell, a prebuilt one will still be a good alternative compared to an Alienware gaming laptop.. There's no excuse for buying a high-end laptop over a high-end desktop if your main objective is to play games..
Just do your research into building a gaming PC, you won't regret it, it's a good learning experience.
If you do consider building a PC, go to the tomshardware.com forum and get advice on components.