Help recommend new computer for Premiere & After Effects, please?

As I'm migrating from Lightroom/Photoshop to Premiere and After Effects, my Surface Pro 3 computer just isn't cutting the mustard

I need something a bit beefier, but my budget is limited to betweet $1000-1400.  I've found a few good options on NewEgg.

I'm wondering if the GTX 1070 is a good card for video work?  Would this card be significantly better than  a lower card such as the 1050?    What about RAM?  I'm choosing between machines with either 16gb or 32gb.  Obviously 32 sounds better, but which would be most useful for Adobe products -- more RAM or a better video card?

Is there a significant difference between I7 machines running at 3.5ghz vs 4.3ghz?  Will I see that different in Adobe products?

I don't play games at all and I'm only looking for a photo/video machine.  I'm hoping to run 2 4k tvs as monitors (I use one quite comfortably with my Surface Pro).  I know the 1070 card is more comfy with 2k and maybe 4k for games, but can't handle the high frame rate for 2 monitors for games --- but I'm not doing games.... soooo

I'd love any suggestions, thanks!!