Depends why you want a helmet.
If you want one purely for head protection, definately go for the Gecko short visor (purely personal preference), and as Andre says, the storage bag. The "inflate to fit" facility should mean perfect fitting, and should you go into the water less risk of "bucketing" (the helmet filling with water and breaking your neck).
If the helmet is required for comms reasons, as well as looking at the Gecko its worth talking to DS Developments as they'll either build a system around the Gecko M10, or using their own, considerably heavier Neptune helmet, which I would venture to suggest would be better for a commercial application.
Hope this helps