I wouldn't be keen on a safety deposit box after the police opened thousands of boxes then assumed the contents of each box to be the result of criminal activities, putting the burden, cost and time of proving otherwise on the vast majority of honest citizens storing items in them. But then again I am a bit of a TFHer.
Police 'took wife's £100,000 jewels' in safe deposit raid
Depending on your own feelings and how much risk you are happy to take you can easily conceal gold coins in your house or in a safe hidden from view in your house. Safe or secondhand shotgun cabinet fixed in the loft then buried under junk and hidden from view. In cupboards, draws, behind bath or shower tray or even sewn in to the lining of curtains. But then you risk armed criminals if they get wind of you buying gold / silver taking it from you or your family by force or if someone knows you have purchased and fitted an insurance approved safe and added insurance cover to your stash.
Depending on how much you intend to spend and your personal risk aversion / TFH you could keep some secure and discreetly at home and some in a deposit box perhaps?