You should be telling people to hold their keys on any full validating node wallet. I dont care if it's Bitcoin Core, Bitcoin Knots, or Armory, but use a full validating node so you know exactly from what chain you are transacting so you just have to be sure of on what chain you are transacting to. I would recommend to stick to Bitcoin Core to not confuse newbies with other compatible lesser known wallets.

So get your coins off Coinbase or whatever shithole you are holding your coins at, put them into Bitcoin Core's wallet and wait for 25th to arrive. You have enough time to sync your node so I don't want no complains later if you don't do your homework now while you can.