It's hard to find a cold wallet that supports XMR and Zcash, as they are often banned/restricted due to their privacy features, which make it difficult for wallet providers to comply with regulatory requirements.
Both Ledger and Trezor support XMR and Zcash, but with XMR you need to connect to a third-party wallet like Monero GUI or Monero CLI to manage your coins. Monero is not integrated into the Trezor Suite app or Ledger Live.
For me, Trezor Safe 5 is the best wallet hands down.
You want to convert to XMR and Zcash easily, but there's no such thing. Good opsec doesn't come "easily".