If you are shipping the ammo to your home address, then you might as well just provide a copy of driver's license. However, if you are purposely not shipping the ammo to a home address in attempt to hide or not provide your home address, then send a copy of your passport ID page, if you have a passport. That doesn't have your home address on it. Other than those...not sure what else would be accepted by a reputable online ammo dealer as ID...maybe military ID.
Are you concerned about something on one of your ID's that you are asking this question?