Jesper + 1st
Holtz + first + B prospect
Nemec + cap fillers?
*IF* the trade were for Bratt, it would be 1 for 1. Either way, I wouldn't expect SJ to want a guy that's only 1 year younger than Meier.
*IF* the trade were for Nemec I would actually expect SJ to included a substantial piece in addition to Meier.
Holtz + First + B prospect is the best bet, however, there are other pieces that could be used. Sharangovich as shown himself to be a decent wing with upside and is being held back by usage. He also has the ability to play Center in a pinch. Mckenzie Blackwood could be in play if the Sharks absolutely demand a goalie and returned back one of their own. I could also see the Sharks demanding Dawson Mercer, but I think the Devils reject that. Seamus Casey may also be of interest to them as he's having ridiculous season in Michigan as a Freshman, but we may be reluctant to let go of him since he's kind of a high-upside wildcard right now, and also has family ties to the NJ area.
As for B prospects, you're probably looking at players like Bahl, Mukhamadulin, or Okhotiuk if they're looking for D. If they demand a Center, the only true center we have would be Jesper Boqvist. Not convinced he would move the needle though.
There's a lot of possibilities.