If they do trade up, the trade values that make the most sense (with the assumption they trade up from pick #23):
#23 + #25 = #7 or 8 - Cardinals or Bills
#23 + #25 = #16 + #46 - Rams
#23 + #52 = #15 - Saints
#23 + #83 = #17 - Steelers
#23 + #102 = #20 - Bears
Likely there would a mid to late round pick or two added on either side in the negotiating. And the pick trade values aren't always perfectly followed so it could move a pick or two, particularly depending on who is available in relation to both teams needs. To me it looks like picks 15-17 are by far the most likely for them to trade up to and would likely be for Sharrif Floyd (DT), Lotulelei (DT), Milliner (CB), Austin (WR), Vaccaro (S), Richardson (DT), Cooper (G), Warmack (G), or Ogletree (LB). It wouldn't make much sense for them to trade up for anyone else unless it is only a pick or two. Obviously several of those guys won't be available in the mid-teens so it depends on who drops a little.
If memory serves me, a future pick in the 2014 draft would be worth a mid round pick one round lower (2014 first rounder is equal to 2013 mid second rounder). But future picks seem to have less hard and fast values so that could swing quite a bit one way or the other. Having 11 picks this year, I would be kind of surprised to see them trade away a pick from next year.