(1) We could create a product that helps people in need.
(2) We can create a product that helps people in need.
(3) We could create a product that could help people in need.
Between those three, (2) sounds the best to me. However, is (1) necessarily incorrect? More specifically, I'm concerned about whether it is permissible to use "helps" after "could." It sounds like some breach of tense agreement, but I can't be sure.