Alienware is a international company apart of dell their expensive but extremely great quality but if you want to go a bit lower tiger direct is a good company never used them since I'm on a different continent (Australia's counted as a continent apparently)
Alienware is horrible. Never buy from them.
Honestly, I'd just order parts and pay someone to put it together if you don't have the knowhow yourself. It's honestly INCREDIBLY simple, and can be done just by reading manuals and such, but, if you really don't think you can, just order parts and pay a professional. You'll still save money and get much better performance and personalization then if you were to order prebuilt.
The Nvida Gtx 200 series would be able to max out the settings in my opinion if not just get something from the 400 or 500 series their very high end through and can get very hot
The 460 doesn't get very hot at all... it gets to about 43 degrees c on Ultra settings with no AA in 1920x1080 Crysis warhead running at a 25MHz overclock. You clearly have no idea what you're talking about.