Both have great potential.
The way I see it, Lisa would have a longer and more consistent career. While JK will probably start amazing but his popularity will scatter.
The reason are : Jk is not fluent in multiple languages which will hurt his promotions, so far has not built his own brand outside of the group ( slow build to a solo is better than a sudden shift), the general public mostly prefers female solo artists ( how many top solos in the west are make vs female?). But he has a stronger and more dedicated fan base ( also less solo stans for the group which will probably continue the support) and his artsy tattoo vibe will sell great in the west
