Do we become the sons and daughters of God the Father or Jesus Christ?
Are we not adopted sons and daughters of God through Christ, his only begotten Son? (Ephesians 1:3-14, John 1:12)
The following additional scriptures have us becoming the sons of God: 3 Nephi 9:17, Moroni 7:26&48, D&C 11:30, D&C 45:8, Moses 6:68, Moses 7:1.
The following scriptures have us becoming sons and daughters of Christ: Mosiah 5:7, Ether 3:14, D&C 34:1-3.
D&C 35:2 blends becoming the sons of God and sons of Christ through the "becoming one" concept. Modern scripture blends the concept of Father and Son into one God and that is Jesus Christ. If Jesus Christ is the Father and the Son, the one and only true God, then I can understand how it would make very little difference if we become the sons of God or the sons of Christ since God and Christ are one in the same.
I personally believe that God the Father and God the Son and God the Holy Ghost are three separate members of the Godhead and that we become the adopted physical sons and daughters of God the Father, attaining the same standing of God the Father's only begotten son and therefore enter into his holy family, becoming one with God the Father through Jesus Christ. We obtain adoption through the sacrifice and atonement of Jesus Christ.