I assume you will be editing video only? No special effects? If so, you can make do with an i5 core and 12-16 gigs of RAM. If you plan on using fancy transitions and color grading then you might have to think about an i7 core. Of course I'm just above you in experience so I'd wait for more experienced voices, but sometimes, they just don't come, in which case, my suggestions are valid.
everything duke said is valid. we don't know what you will be doing though. 2k is i5, 4k is i7 needing 8 threads. any resizing a good gpu is recommended. any largely uncompressed video codecs will require a SSD if bitrate above 100mb/sec.
good budget gpu: 1050ti as 1060,1070,1080 prices have doubled. if you want to wait, there will be 6 core laptops soon.
there are some money saving tricks, proxy editing for slow cpu. small proxy files for slow hd's. no resizing or noise reduction in the timeline.
what does buying a gpu get me?
some effects (complete list at the bottom of this post)
scaling (details here)(big one here for downrezzing 4k to web 1080)
color space conversions
I use PC's and Macs and will agree that if you can go with an i7 processor with as much ram as you can afford you are on the right track, I would lean towards Mac not only because they are really stylish but also super reliable and the real winner is watching your output files on it is awesome (Like night and day) and if you are ever to show your clients in person it would make a much larger impact.
That's only my opinion though.
"There are those who may,
And those who will,
Or so they say.
Lastly there are those special few,
Who say nothing -
But in their actions DO! (HH)