That'll work. Updated.
Construction
To create a magen requires a custom built laboratory equipped with an electrum-lined mold. This mold defines the shape of the magen (humanoid, equine, canine, lizard etc). The total cost of this laboratory is 15,000 gp, but it can be reused to make multiple magen of any type (Demos, Caldren, Hypnos et cetera). Additional molds to create magen of other shapes cost 5,000 gp apiece.
Constructing a hypnos magen requires exotic alchemical reagents and tinctures costing at least 1000 gp. Molding the body requires a DC 12 Craft (alchemy) check.
CL 5th; Craft Construct, animate dead, charm person, shocking grasp, suggestion, caster must be at least 5th level; Price 5,000 gp; Cost 3,000 gp + 160 XP.
Gah!
I just realized the original description says "Wizards never shape them to resemble animals or monsters, but sometimes give them bestial features", meaning the sample shapes for the mold was all wrong.
It needs changing from "(humanoid, equine, canine, lizard etc)" to something like "This mold defines the shape of the magen (male or female; human, dwarf, half-elf or other humanoid race)."
Demos look pretty straightforward. I'd just make them three Hit Dice Medium Constructs with +3 natural armour, a bit of SR and some weapons.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.