Which Star will fit mie?

Good pun in the title.

Personally I would've gone for the highest IV one, considering moves doesn't matter for you. I think it's worth the extra stardust. But number 1 is also a good choice.

Highest IV one (3) followed by (1). Starmie is really rewarding if u know how to dodge well, u can dish out more dmg than a vape or a kingler and water gun is a great fast move that is unavailable on gyarados. I have a 97.8% IV one with WG/HP that demolishes rhydons golems and fire types in gyms way faster than any of my vapes while being extremely potion efficient( a level 30 starmie with 15HP ATK only needs a revive+ yellow potion(heals 50hp) to return it to fighting status)

The second one. A great Moltres attacker.

Starmie is a glass cannon, and Water Gun has a short cooldown. Also noting that Power Gem is slightly less risky.

Don't waste TMs on Starmies, there are a plenty of better options in the game like Machamps.

The third one has great IVs. I'd be happy to go with him.

I think some people are trying to collect all types of Hidden Power Starmie which sounds like fun...I'd consider powering up a good type (like Rock for now), hidden power Starmie which you could actually use against a raid boss...

Safest is just to do #3 since it has high IV and you won't find many better...

I have 2 at 97 and 3 at 93 all at lvl 20 Rarely use them anymore. They remind me of crown of thorns starfish, a big pest on the Great Barrier Reef. But I digress. Of yours number 3.

Hey there, I am lvl 40 and I can tell you stardust gets incredibly precious as you level up. When I was at level 30 I thought I would have enough stardust to power up tons of pokemons but I was wrong. As you level up and so your pokemons too, they get incredibly stardust hungry. I know starmie is your favorite pokemon but you don't have to love it less even if you don't power it up. Keep your stardust for now and allocate to higher tiers pokemons. I know starmie has a high base attack stat but its def and sta are not fantastic and may not last long in battles especially raid battles. There are also more generations of new pokemons arriving in the future. Just my few cents worth of comments. :-)

I wouldn't power these up, but if its your favourite, then you are going to anyways. I would try to get double rock starmie - not sure if TMs will change Hidden Power types though...But I think there is room in the current meta where double rock starmie would make sense...otherwise double water.