The Protestant tradition that captures what you're looking for best is probably the Lutheran. I find their Christology very attractive. I just don't think it's true. As far as I can tell, all of the strands of the NT see Jesus as a human person. It's a hard judgement, because of course the question hadn't arisen in the 1st Cent. So nowhere will you see a statement sufficiently explicit to rule out anhypotasia. But it seems an unlikely reading of what the NT writers say, and seems more likely a result of popular piety. This does not reject the Trinity. All major versions of liberal theology are Trinitarian. Unfortunately for our future as a nation, there are lots of things that are attractive that aren't true.
I believe you are following somewhat of a non sequitur. Your argument seems to be "all of the NT aees Jesus as a human person." Setting aside the fact that that is strictly speaking untrue, for example, John 1 describes him emphatically as a divine person, and Matthew 28:19 enumerates him as one of the three prosopa of the Trinity, you seem to be under the misapprehension that accepting the completeness and perfection of our Lord's humanity requires some form of concession to Nestorian thought, when it, from a Patristic soteriological perspective, does not.
I would argue the hypostatic or, as we would say in Oriental Orthodoxy, the natural theandric union, are attested to by verses such as "He who has seen the father has seen me" and "I and the Father are one." Every member of the Nicene Church and its offshoots, including Oriental Orthodoxy, accepts the full humanity of our Lord as well as His complete eternal deity.
Indeed, the paramount importance of the completeness of our Lord in both His humanity and divinity is found throught the writings of the entire apostolic church, as essential to our salvation. Consider this: practically all of the soteriology of the early Church, including the Nestorians, the Chalcedonians, and the Miaphysites, rested upon the idea of God glorifying our human nature through a participation into it. The Nestorians merely wished to preserve to the fullest extent possible the ideas of divine immitability and impassability, which are scriptural, but their zeal suggests also a whiff of Platonic philosophy.
Their perspective became a minority perspective I would argue based on the immediate logic of
communicatio idiomatum, as best expressed in the hymn
Ho Monoges, composed by St. Severus from the words of Sts. Cyril and Athanasius, and sung at the beginning of every Syriac Orthodox divine liturgy, and later introduced into the Eastern Orthodox divine liturgy by St. Justinian (where it is presently sung at the end of the Second Antiphon), in expressing how our Lord glorified our fallen human nature by condescending to assume it, restoring it to not only accurately bear his image but to the point of facilitating our own deification (see St. Athanasius).
The blood-atonement/penal sunstitutionary idea of soteriology really began with Anselm of Canterbury based on a knowledge of St. Augustine not tempered by a knowledge of the Greek fathers, and I would argue that Calvinism represents the apex of this soteriological error, to the extent of embracing a semi-Arian position and rejecting the coequality of the divine logos with Federal Vision theology (which I would assume that the PCUSA, to its great credit, has always completely rejected). It seems to me that one potential positive aspect of liberal theological thought in the PCUSA is a potential openness to other soteriological models, particularly the ancient one as expressed by St. Athanasius, the Cappadocians, St. Cyril, St. Severus, St. Maximus the Confessor, et al.
By the way, this marks the second occasion of my having met a Calvinist who wanted to believe in a different doctrine but regretted being unable to based on their own theological analysis. In her case, she seemed resigned to accept the idea of predestination, unconditional election, and conversely, unconditional damnation, based on what she had been taught within Calvinism, but she had no knowledge at all of Patristics.
In your case on the other hand, I strongly suspect you have great erudition in this regard, to which end I would dncourage you to study the writings of Mar Babai the Great, Catholicos Timothy, or St. Isaac the Syrian, all prominent members of the Nestorian church whose theology nonetheless seems to negate and undermine your objection to communicatio idiomatum.
Lastly I would note communicatio idiomatum could take us i to the realm of Eutychianism if we were to delete the important implicit qualification "in the flesh," which is explicit in the hymn
Ho Monoges. In other words, the eternal and uncreated God was born, in His assumed humanity, but He was not born in His divinity, but rather begotten of the father before all ages. Likewise God walked upon the earth, and God was buried in a tomb, but again, only in respect of His humanity, because according to His divinity, the God we pray to is "everywhere present, and fillest all things," and completely unbounded and uncircumscribed (the great error of the Samaritans being to assume a specific localized presence of God upon Mount Gerizim).
Increasingly I am inclined to regard
Ho Monoges together with the Nicene Creed as the ideal test of Christological Orthodoxy; if someone will recite the former, they reject the errors of the Fourth Century, and if they will sing the latter, they reject the errors of the Fifth, Sixth and Sixteenth centuries (and if then upon confessing the Creed and singing
Ho Monoges, they embrace iconoclasm, they contradict themselves fairly dramatically).