If the only thing you need this carrier to do is a hip hold, I would go for a pouch or a ring sling. They both really shine in that position. The Moby is probably not going to be supportive enough if your baby is older then say 4mo, because the material is stretchy, plus it's a lot of fabric just for a hip hold... you'd be better off getting a shorter length woven wrap if you like the idea of just using a piece of fabric. And while the Ergo is a good front and back carrier, I would not recommend it for a hip hold; while it's a possible position it's usually not very comfortable (shoulder strap rides up on most people) and would probably be pretty bulky for just wearing around the house.
So yeah, I'd go for a ring sling or a pouch. A dedicated hip carrier, like the Scootababy, would also be a good choice but it's kind of expensive. Very comfortable though! Good luck in your search.