Issue with Fox is that hes set to be a UFA and can choose to sign with anyone.
I'd do Fox and a conditional 1st.
If the Rangers can get him inked before the draft, the pick reverts to a 2nd in 19. If they cannot, the 1st in 19 goes to NYR
Fox is set to be a UFA going into the 2020-21 lockout season. Not next year. And he stated this week in a The Athletic article that his #1 goal is to be in the NHL as soon as possible.
Only the Canes (or a team that trades for his rights) can sign him to a McAvoy-type deal where he starts next year on year 2 of his ELC. And he can’t choose his own destination as a college UFA for an extra year beyond that.
With that being the case, the earliest that Fox becomes available for trade is when he refuses to sign at the end of this year, eliminating the acceleration of his ELC. Until then all signs point to him signing in Carolina.
If the Rangers wanted to offer that benefit themselves then they would have to convince Carolina to concede it. That would be pricey for the calibre of prospect Fox is showing this year in the NCAA.