Since you are working with altcoins, I don't see the point in adding a 3rd hardware wallet to the mix. I don't have a a lot of positive things to say about most altcoins anyway.
Storing BTC can using multi-signature wallets, which provide a highest secure guarantee. However, for storing altcoins, only single-signature wallets are available. Currently, there are a few well-known open-source wallets for altcoins, including Trezor, BitBox, OneKey, Keystone, and KeepKey.