Zoro does not rely on Devil Fruits, but if he were to eat one, the Buki Buki no Mi would allow him to transform into multiple weapons, expanding his combat options.

In one piece will Sanji, Zoro or Ussop get a devil fruit? Zoro definitely won't, he wants to become the strongest swordsman with his own power, not a devil fruits power. Unless the clear-clear fruit gets in sanji's hands, he won't eat any devil fruit, he stated that himself.