One could diversify with a basket of different vehicles with some of the miners and SLW. There's always some risk in any. Scrap coins ( non numismatic value ) good for any disaster scenario. Bars and other pure hard choices often difficult to value and trade.
AGQ is all paper...done with leveraged futures, pretty risky.
I like CEF http://www.centralfund.com/ This not a pure silver play it holds both gold and silver, If you hold it in a taxable account, and file the correct paperwork (Form 8621)long term gains are not taxed as collectibles. This is a closed end fund.
Buy the real stuff. Not coins or jewelry. Just junk, rounds and low premium 10 oz. or 100 oz. bars. Nothing safer than that. If things go to hell who cares about numistic or collector value, a guy's got to eat!