My pragmatic prediction; Mannequins will be a 50-61 level craft (likely carpenter, Armorer or weaver) and when placing it, it will be treated like placing a Housing NPC where you can choose its gender and race and when interacted with, it will act have the same Glamour/dress up menu that Squadrons have. It will be made up of level appropriate Mats or a new type of mat (so no one can just make them out the gate for whatever reason)
Apartment/FC room: 1
Cottage: 1
House: 3 or 4
Mansion: 6 or 8