As a fellow 17″ laptop sherpa (with the elongated left arm to prove it), the rule of thumb is go for the fastest, most advanced, biggest, baddest (add your own adjective here) you can – the minute you walk off the lot, it’s obsolete.
That being said, the most important consideration is the card. I don’t have the list in front of me but because there are fewer cards available to portables, make sure the one you are looking at is qualified by Adobe AND make sure the specs you are looking at is for the “M” designation (for “mobile) and not for the same named card that gets wedged into a desktop.
I always worry about these “gaming bundles” as the card tends to be aimed at that crowd. Nothing wrong with the 10series cards but we’ve had better grunt with the MQuadra models, at least for AE. The tide is changing where the Cuda cores are starting to make a real difference in AE production but I think horsepower is still the main focus – that, and read and write speed on the drives. I’m not sure I trust SSD’s for long term yet (C4D might just kill one with its million reads and writes on every frame) but you should see a massive speed increase with heavy AE projects if you swap out the HDD (and if not check the speed of the internal HDD to make sure its fast).
As for 4K, keep in mind the icons gets smaller at that rez (and some of AE’s are way too small already – I’m glad we have the new “Close all other timelines” button because those little close X’s… well I don’t think you can resolve an X in less than 4 pixels, but Adobe sure is trying.
Can you really see a difference in a 4k screen at any size that will be portable? Many of these 4k screens just goose the color so they “feel” sexier but in fact look as sharp as HD or 2k. Some 4Ks will also just scale the HD and add artifacts and artificially sharpen the image, so what you see may not be what your client sees.
There are a zillion ways to look at this – let the pile-on begin!