[member="Elpsis Kerrigan-Alcori"]
OK, so I'm brainstorming here, but this is my idea.
Process a human, but instead of putting the consciousness into an HRD body, put it into a clone. Yes, it has the weaknesses of being much easier to destroy, but with a droid brain behind it to filter out some of the more obnoxious organic issues they'd still be an excellent infiltrator and undetectable.
But if that's going too far, you could make an even more 'human' HRD by making the polymer even lighter, and removing all metal parts. That'd do the same thing as the above, but could be a little easier detected.
Depends how far you want to go.