I don't know anything about emulsion making but I'm selling laboratory equipment.

Magnetic stirrers a great with low viscosity liquids but have limits with higher viscosity liquids.

In my opininion, from the specs I have read here, a overhead stirrer with a paddle stirrer would be the better tool for the job. You don't have to care about viscosity, get good mixing results at low speeds and 3000 ml can be managed without problems.