They're also said to be both horrifyingly expensive and horrifyingly unethical, so they'd be very difficult to mass-produce. I'd say to be careful with one, and maybe treat it less like a Resident Evil 4 character, and more like Nemesis, from RE 3. Show a scene of a camera feed of something breaking loose and effortlessly vivisecting everyone, sending the message that they need to avoid a direct confrontation until they can acquire a rocket launcher.
As for making one, all I can suggest is something general: pick someone with high Attributes (with possibly CHA, or INT or something as a dump stat), not necessarily using PC stats because a lot of money was sunk on this, and add cyberware (potentially all Delta grade) until the poor thing's Essence is at somewhere like -2. Give it a mobile background count, as blood magic is needed to make the whole setup work (and to make it more resistant to spells/unnerve spirits), and give everyone possible escape routes. PCs, to tip them off that a stand-and-fight mentality would be a bad idea, and your cyberzombie so it can escape in the event that the PCs do manage to cheese it.
As for Silent Hill-related horror, that sounds like it'd probably be better suited to a metaplanar quest. One where all the spirits want to scare you and gross you out?
