Well, the problem is that the soul has to be something tangible, or it would keep getting left behind during transport.
And I would love to see the religious bend-over-backwards explanations as to how a soul binds to a machine instead of the brain.
I'd think maybe Data would notice that some weird energy field was attaching itself strangely to his positronic net. And the fact that deleting his ethical subroutines does not trigger this imaginary soul to compensate.
Or that Thomas Riker and William must now be in possession of half a soul each, Voldemort style.
Or that creatures resembling this aethereal form, energy born, seem to be largely evil or devoid of anything a soul is meant to impart. Strange, given that they're the closest to it.
Sorry but, really? Data may never exist in any form at all no matter how advanced our technology becomes. He acts the way he does because of the script and an entirely Human actor dictating that he does.