Lapras Power up

FB BZ, because FB IB you'll have to max out for PvP. ???

Power up the FB IB one. All three of your movesets have good attacking movesets, but water gun is terrible on defense, and ice beam is a better charge move on defense than blizzard.

Also, how did you get 3 laprases with high IVs?

If your looking for one for attacking then the 89% one. If your looking for one to place in gyms the 96% one. The 89% one can be good on both attack and defense but that's if it can get its charge move off on defense either way, those are some nice Lapras you got there.

Mixed-type W/B is unfortunately not good for attacking Dragonite so I wouldn't invest anything in it no matter what its IVs.

Both F/I and F/B are good for attacking. Blizzard does a bit more damage, but Ice Beam can be used more often with less wasted energy and damage.

If you ever fight enemy gyms with other players, the benefits of multi-bar charge moves far outweigh the extra damage of one bar moves. Two players unleashing both their 100 energy moves at the same time to obliterate a defender is usually overkill and a lot of wasted damage potential.

Water Gun on Larpas is useless.

Power up the FB/IB one, but maybe up to 1700 CP only (You don't want too high CP, otherwise it won't be a good prestiger.)

Do you want a Lapras for Atack our Defense?

I would power up the no. 1. FB/BZ is slightly better than FB/IB, but the difference in IV is quite a gap and 96% IV lapras is super rare. I would not even consider the no. 3. The only thing lapras is still good at is attacking dragonites and we know water-type moves deal ineffective damage to dragon-type mons.