In English transliteration of Hebrew and Aramaic, the "K" is rendered either with "K" or with "C". Thus you will sometimes see tanakh and sometimes tanach. It is purely a matter of preference.
I admit I have no qualification whatsoever. I even wonder why I allow me to get myself trapped into areas where I have no knowledge.
I defer to the Catholic Catechism which states unequivocally that it was the "Confession" of Peter, not Peter, which is the "Rock".
424 Moved by the grace of the Holy Spirit and drawn by the Father, we believe in Jesus and confess: 'You are the Christ, the Son of the living God.' 8 On the rock of this faith confessed by St. Peter, Christ built his Church.
Woops - you forgot to read the whole book to get the context. Here is what else the Catechism has to say about St. Peter:
CCC paragraph 881: The Lord made Simon alone, whom he named Peter, the "rock" of his Church. He gave him the keys of his Church and instituted him shepherd of the whole flock. "The office of binding and loosing which was given to Peter was also assigned to the college of apostles united to its head." This pastoral office of Peter and the other apostles belongs to the Church's very foundation and is continued by the bishops under the primacy of the Pope.