Not a Solo-Series, because I didnt like his last Solo-Series (after he came back and lived in Smallville with Martha Kent and Krypto and went to Smallville School).
BUT I would LOVE a Series of Cassie,Conner and Bart...aged up to the age of 20 and living in a house in Hawaii.
So more the ToT Versions (heroic versions) with different Code-Names and Outfits.
This would be the perfect solution because you can bring elements of Kessel Conner in Hawaii, Johns TT Conner back and mix them:
from Kessel Superboy: freedom (outside of Smallville),TTK, characters like Roxy, Knockout etc. etc. with the attitude of this Superboy Version
from Johns TT Superboy: power level and history, Cassie and Conner relationship,....
It would also help the other 2....