Hello,
where is the best place to stock ark ? I don't want check every month it's for long term.
Thanks in advance.
If you're going for the "best" that would be a hardware wallet.
I'm using Ledger Nano S for that purpose.
If you want the 2nd "best" method when it comes to the safety of your private key, then a paper wallet will be enough as long as you don't lose the paper.
You can find the official paper wallet generator here:
https://arkecosystem.github.io/paper-wallet/