The first one is the winner , ir the "keeper" in that batch of seedlings IMO. It's the frostiest by far, and the quickest obviously. I'm sure the other phenos will get more crystal as they mature, but I can just about promise you that one is gonna stay the frostiest. Frosty means potency, and flavor usually too, so I WOULD TRY TO CLONE A LOWER BRANCH AND REVERT IT, YES IT'LL TAKE A WHILE, AND SOMETIMES THEY DON'T MAKE IT, SO TAKE AS MANY AS YOU CAN. Then when it's done, if the clones havn't rooted and are healthy, you can leave some foliage on and revert the whole plant, but I would try to copy that one cause it looks like a better pheno for sure. The other ones that take longer might yield more, but the quality could be alot less. Any time your growing seeds, your gonna have some variation like tha, and there's always 1 that stands out aove the rest. That's why I always clone ALL seedlings so I have a copy of the special one when it does pop up.
They're lookin great your doin' s good job, keep it up!