No question that Karlsson is a keeper, and if you need a goalie then Fleury makes a lot of sense. I'm not so sure about Eberle though. If you are set on those three though, I'd definitely take Backstrom as your 4th guy.
Having said that, I'd probably take Staal or Kovalchuk over Eberle. Kovalchuk has said he's going to come back to NA after the KHL All-Star game, and he's absolute dynamite for PPP, which your league gives special emphasis to. Additionally, I'd be looking to grab a bunch of top centers if your league counts FOW but doesn't specify forward positions. Having Backstrom and Staal would be great for that.
The reason I'd leave Eberle off the list is because he doesn't provide as much peripherally as the others. Staal has great FOW, and SOG numbers as well as solid PIMs. Kovalchuk is one of the best SOG guys out there. Eberle only had 10 PIM and didn't crack 200 SOG last year.
My final 4 would be Karlsson, Staal, Backstrom and Fleury. Hope that helps.
16 team, full keeper
19 roster players, 15 prospects
Stats: G, A, PPG, SHG, special teams assists, SOG, FOW, PIM, hits, blocked shots, +/-, W, SO, saves, s%, GAA, shootout saves
C: Crosby, Backstrom, H. Sedin, Boyle, Brassard
W: Voracek, Burrows, McDonald, Filppula, Dorsett, Hudler, Abdelkader, Bouchard, Ott, Zuccarello, Stalberg
D: Karlsson, Letang, Enstrom, Boyle, Giordano, Gorges, M. Stuart
G: Quick, Kiprusoff, Ellis
Prospects: Granlund, Pirri, Caron, Killorn, T. Johnson, Galiev, Corrado, Vatanen, Moore, Rundblad, Bachman, C. Johnson, Desjardins