If Linux is on the list I usually work from the GPU/CPU outward. Less hassle and best graphics performance linux-wise if you get an nVidia powered notebook, then next would be the CPU, beefy enough to do whatever job.

I'd get the best I can on those two specs. You can always throw in more memory/storage later on. Other "can't change things" to consider if using on the go is keyboard, mouse input (trackpad/nub), display size/resolution, and battery.