What you have its already good. Later game you will want powerful ninjas like Asuma wind blade, Pein- Shurado, etc... Your ultimate goal is to have at least the Invincible Kitchen Knife Lighting team which is
Lightning main + Asuma (wind blade) + Guy + Shurado.
http://forum.naruto.oasgames.com/en/data/attachment/forum/201607/13/190647xfr4yjehr0eno9ef.jpg
http://oi66.tinypic.com/2jaylb5.jpg

You can get those ninjas from:
● Shurado can be obtained from the tendo treasure.
● Asuma (wind blade) is available in the shops.
● Guy can be found in the seal treasure, Elite instances and survival trials.