ROR seems like Palat 2.0. That kind of player is exactly what the Devils need - great defense and chips in enough offense - but he is no longer what he was. And certainly wouldn't give up anything significant for him at this point. At best, a 2nd and B-tier prospect.
The cheaper set of players - Evans, O'Connor, Tanev, etc. - seems more likely. Maybe even two of them if possible.
I'd also say that people are proposing a lot of players I like - Backlund, Coleman, Tanev, ROR, etc. - but missing the real problem. The Devils get stops from their bottom six, defensively they're fine. The issue is depth scoring. Quite a few of these guys are barely above Haula as far as career averages.
That being said, I will say that Backlund, ROR, Coleman and Tanev are more likely to do hero shit in the playoffs than our current bottom six.