I have found one thing that you need to take into consideration. If you use heavy 3d software, you need to consider finding an engineering class laptop. The gaming laptops use video cards that are good for high paced video game graphics, but they tend to suck when you want to get the same results out of them for engineering type 3d work. If you use 3d software, I would suggest that you ask for laptop recommendations from them as to what graphic cards work well with their software.
I have a Toshiba i7 with 8gb ram that is 1 year old. It runs Alibre great, but the rendering under SprutCam is average at best. To get semi-good performance, I have to switch the laptop to full power mode (keep that trick in mind too). A friend has an engineering glass video card in his computer, and I tried running Sprut on that. Very big difference. An engineering quality video card runs circles around the gaming card in my laptop.
I would also NOT considering using Windows 8. Downgrade as fast as you can to Windows 7.
Wade