On a "four bottle ride" you probably don't need anything but water. But, if you want a sports drink, then get whatever tastes good to you. Vitamin fortified water is a gimmick. You don't need vitamins added to your water for bike riding. You should be getting your vitamins from the food you normally eat. You drink a sports drink to get some carbohydrates and a bit of electrolyte. Any brand at the convenience store is going to provide these so it's just a matter of what tastes good to you.