Blissey evolving strategy

its well recieved that the best blissey would be the one with the highest atk iv. i would say compare 1) and 3) for that and choose among 1) and 3)

all of blisseys attacks are pretty good. its attacks are either STAB or check its own counter of fighting type (zen, dazz, psychic)

You can pull the IVs and check the exact max CP below.
Now the more difficult question is will you go with something that has a smaller max CP but requires less powerups or a larger blissey with higher power up costs. I think thats a question that will best be answered by yourself. My opinion works for my area and my playing style but may be horrible advice for where you play.

https://pokemongo.gamepress.gg/cpcalc#/