Which secure BTC Wallet do you recommend for me to hold?
None, until you learn to do it right. You should at least try to narrow down what went wrong with your Ledger wallet and what resulted in you losing the coins you stored there. Ledger is no longer a recommended hardware wallet, but for other reasons that have nothing to do with this case of yours. No hardware wallet will help you if you have no idea what you are doing or how to protect yourself online.
~snip~I think you gave him the best possible answer, now the only question is whether he will understand and listen to your advice. If we exclude some problematic hardware wallets, then in general we can say that the weakest links in the security chain are still people who do not understand that the most common attack vector is their backup, not the device itself.
No matter what HW he buys, the same thing will happen to him if he doesn't keep a backup, PIN or any other important information in a safe way - which means completely offline and away from other people's eyes, including those he trusts.