Maybe I'm in the minority here, but I think defense is mostly covered in terms of prospects and the focus should be on skilled forwards who can score, or modern day grinders who can skate.
On D, K. Miller has pretty much established himself as the #1 prospect for that position, and then there's Lundkvist, Hajek, Lindgren, Rykov, Keane, Crawley, and also Ragnarson and Gross. I'm not counting guys like Day, Bigras, or Sjaalin. That's a lot of guys and I'm not so naive to think that everyone of them will suit up for the Rangers, but most will cross paths in the organization.
The only exception would be is if a stud is coming back in a much larger trade like a Dougie Hamilton or a Parankyo.
Rangers need to add talent up front. They need guys on ELC who can score, or tweeners in the style of Hagelin that can be elite sidekicks and drive play. We all have high hopes for Kravstov and adding Panarin would be dynamite along with a high #1 pick, but they need depth throughout the lineup. Need to develop or Hornqvist/Arvidson type badly. Closest they had to that recently was Petr Prucha who scored 50 goals his first two years in the league but wasn't durable enough to sustain that level of scoring.