This new atomizer by ThunderHead Creations sports an overall diameter of 24mm, so it'll fit most of your devices with zero overhang. In addition, it's primarily constructed of 304 stainless steel. It does include a wide bore drip tip, and it is compatible with 810 drip tip sizes.
Also, it has an e-liquid capacity of either 2ml or 4.5ml (with the bubble glass tank section). Filling it can be done quite easily with its top fill system.