I can't comment on that particular video or the software he uses, but the Blockstream Jade is safe to use. It's an open-source and airgapped bitcoin-only hardware wallet. You can use it as a stateless signer via QR codes if you want. You have the choice to purchase the assembled device, which is very affordable and should cost you around $65, or you can purchase the individual components yourself and assemble everything on your own and build it from source.