As a 9550 owner owner I would suggest purchasing it from Microsoft Direct because you can use an education discount which saves you a few hundred. Mass storage wise I see myself in a few months ofloading to an external hard drive or external SSD every so often for file dumps. But for more and more things cloud storage is used so the space will be less of a constraint. But yah, I would go with atleast 16 gb of RAM. For engineering are you sure you don't want a Quadro, have you looked into Lenovo's Mobile Workstations?
Yoni