Sorry, I don’t personaly know of any “Protestants” that believe that the Rock refers to Peter himself and not his confession.
Oh sorry for the assumption. Here are some,
taken from catholicoutlook.com/rock.html
D.A. Carson explains:
Although it is true that petros and petra can mean “stone” and “rock” respectively in earlier Greek, the distinction is largely confined to poetry. Moreover the underlying Aramaic is in this case unquestionable; and most probably kepha was used in both clauses (“you are kepha” and “on this kepha”), since the word was used both for a name and for a “rock.” The Pe****ta (written in Syriac, a language cognate with Aramaic) makes no distinction between the words in the two clauses. The Greek makes the distinction between petros and petra simply because it is trying to preserve the pun, and in Greek the feminine petra could not very well serve as a masculine name. . . Had Matthew wanted to say no more than that Peter was a stone in contrast with Jesus the Rock, the more common word would have been lithos (“stone” of almost any size).
Protestant scholar Oscar Cullman, writing in the Theological Dictionary of the New Testament, writes,
The Aramaic original of the saying enables us to assert with confidence the formal and material identity between p tra [petra] and P tros; P tros = p tra. . . . The idea of the Reformers that He is referring to the faith of Peter is quite inconceivable . . . for there is no reference here to the faith of Peter. Rather, the parallelism of “thou art Rock” and “on this rock I will build” shows that the second rock can only be the same as the first . It is thus evident that Jesus is referring to Peter, to whom he has given the name Rock. . . . To this extent Roman Catholic exegesis is right and all Protestant attempts to evade this interpretation are to be rejected.
Protestant Greek scholar Marvin Vincent wrote,
The word refers neither to Christ as a rock, distinguished from Simon, a stone, nor to Peter’s confession, but to Peter himself, . . . The reference of petra to Christ is forced and unnatural. The obvious reference of the word is to Peter. The emphatic this naturally refers to the nearest antecedent; and besides, the metaphor is thus weakened, since Christ appears here, not as the foundation, but as the architect: “On this rock will I build.” Again, Christ is the great foundation, the chief cornerstone, but the New Testament writers recognize no impropriety in applying to the members of Christ’s church certain terms which are applied to him. For instance, Peter himself (1 Peter 2:4), calls Christ a living stone, and in ver. 5, addresses the church as living stones.
Protestant scholar W.F. Albright wrote,
This is not a name, but an appellation and a play on words. There is no evidence of Peter or Kephas as a name before Christian times. . . . Peter as Rock will be the foundation of the future community. Jesus, not quoting the Old Testament, here uses Aramaic, not Hebrew, and so uses the only Aramaic word which would serve his purpose. In view of the background of vs. 19, one must dismiss as confessional interpretation any attempt to see this rock as meaning the faith, or the Messianic confession, of Peter. To deny the pre-eminent position of Peter among the disciples or in the early Christian community is a denial of the evidence. The interest in Peter’s failures and vacillations does not detract from this pre-eminence; rather, it emphasizes it. Had Peter been a lesser figure his behavior would have been of far less consequence (cp. Gal 2:11 ff.).
David Hill, a Presbyterian minister at the University of Sheffield wrote,
It is on Peter himself, the confessor of his Messiahship, that Jesus will build the Church. . . . Attempts to interpret the ‘rock’ as something other than Peter in person (e.g. his faith, the truth revealed to him) are due to Protestant bias, and introduce to the statement a degree of subtlety which is highly unlikely.