@Kentucky Fried Torchic Thank you for the update! :)
Are you able and allowed to evolve your Pokemon by trading? If so, I vote for Abra. If not, I vote for Eevee.
Regarding Jason, you should probably level him up, evolve him and use him against Whitney, then send him back to your PC. Double Kick is not that powerful in the long run and he won't be able to evolve into Nidoking anytime soon.
Good luck with your adventure! o/