Zhou Enlai is the most obvious candidate for this. Ultimately down the line, since Zhou was a moderate who advocated peaceful coexistence and less radical domestic policy rather than a hardcore ideologue like Mao was, while I doubt Chinese intervention in the Korean War could be avoided, things like the Great Leap Forward, the Sino-Soviet Split and the Cultural Revolution could definitely be avoided.
I doubt there would even be much of a power struggle, if any, since this was before Mao is considered to have gone mad with power, and there was a clear line of succession within the Party for who would take Mao's place.