Searching and Googling doesn't really provide much info, and the technology seems pretty new still.
Wondering if someone can give some input.
A normal bitcoin paper wallet generated in all the normal secure ways will work fine. Send the coins to that wallet address.
When you want to spend them then download and sync up the Blockchain with the Omni Layer full node and import the private key.
Yep, you can send any Omni/Counterparty asset to regular Bitcoin cold wallet and later retrieve it by restoring the private key. I have done it before and can confirm it works.
Hmm, I am not familiar with the ledger nano S. I gues it is a hardware wallet? Any wallet, whether it be a hardware wallet or not, where you can retrieve the private key to your Bitcoin address would work for Omni/Counterparty assets.