That Asus N53SV-EH72 15.6" notebook is looking good @ $950
Core i7 2670QM(2.20GHz Turbo mode to 3.1Ghz for single CPU), 6GB RAM, 500GB HDD 7200rpm 15.6" 1920x1080 LCD w/ NVIDIA GeForce GT 540M graphics.
2yr warranty plus 1yr Accidental Damage coverage.
6lbs, USB 3, WiFi/Bluetooth 3.0, 2.0MP webcam. A lot to like here.
Solidworks is multithreaded.
6GB RAM is recommended.
About graphics cards:
nVidia Quadro FX series or ATI FireGL/FirePro series. Although SolidWorks might work with any generic graphics card, a graphics card with hardware OpenGL acceleration will provide superior performance
all the laptops have quad core i7's yes but they have crappy gpu's. on top of that they are gaming gpu's so they just are set out to do the work you want them to do.
with the desktops while they all have quad i7's the gpu's your getting are lacking for the money. i built the pc in my sig for at or below those prices and mine will be a lot faster + overclocking ability.
you should build your own or find a custom builder that doesnt charge a lot you can build much better then that yourself and building a computer is not hard at all. pretty idiot proof really.