Didn't they say that copying logia fruit was difficult. So I think he would have a different but appropriate devil fruit power. Something that would let him do something like drying an enemy out, like maybe that rust fruit that marine from water 7 arc. Or something that lets him break into small pieces, like Buggy's fruit, or the Balls fruit that marine had in water 7.

I expect only the first 7. I honestly don't want the to flood the series with clones. I think they will only serve as fodder bosses in the final arc, or to give the stronger Strawhat allies something to fight.