Lapras Power Up

Actually CP doesnt always matter try on the one with the best IV.

I would go with 2 aswell. Best IV, best attacking moveset (imo by far) and still a really nasty defender, although it will end up at the bottom, unless you have an organized group of players, that will put multiple Lapras, Slowbro, Omastars or Wigglys in gyms and dont care about CP but for actual combat power.

2 definitely, good IV, good moveset and decent level.

I would invest in Lapras #2 with no hesitation and no regrets!

What is your motive for powering up? I think all of these are high enough level to be decent attackers into anything weak to ice (dragonite, rhydon, golem). (1) has the best move set for defense. The higher IVs of the other two, still won't get you top spot in any gym near me.