The set up you're using would be much more effective with wind main. But if you want water team:
1)use Iruka... - he's great for ninetails with every chararcter, his buffs are very effective;
2)you need a water barrier.. so it's Haku for you untill you get Mei or Darui.. you may want to upgrade his stars, he's actually pretty good once you upgrade him;
3)ten-ten untill you can replace her with gnw ten-ten.. her chase and buff is still a good for WB. As well more stars would give you a better result.
4)use Ton-ton for summon, as he's deals more damage than Chameleon.
P.S. Water main will become much better at Nine Tails with the new skills, but I'm not sure how they progress with your level.
P.P.S. At this point the greatest damage you can deal to Fox would be with wind main.
Hope this helps.