Hello, I'm planning to buy a hardware wallet for myself.
I wonder if you need to synchronize your wallet from time to time in order to make sure your cryptocurrencies are not lost or something?
Another thing is - can those wallets break down over time so you won't be able to run them? What then, have you lost all of your cryptos there? Or what if you simply lose your hardware wallet, is there any remotely based recovery option?
Can any kind of malware steal your funds or private key or anything at all?
And what is the best hardware wallet in your opinion and why (compare it to others if you can)?
Both Ledger and Trezor offer a browser-based user interface that is basically a thin-client, so you don't need to synchronize your wallets, the servers of the respective hardware wallet providers will do it for you.
If your hardware wallet breaks down, you can use the wallet seed (ie. the random word list that is used to generate your addresses) to restore either to a new hardware wallet, or a software wallet such as Electrum. This way you can also recover your coins in case you lose your wallet, so always keep a backup of your seed on paper in a separate location.
There are no known vulnerabilities by which malware can steal the private keys of your hardware wallet. Should the paper backup of your wallet seed be stolen however, it is recommended to move your coins. Either way you should have an additional passphrase set just to be sure.
I personally use a Trezor, but Ledger seems to be equally recommendable. Ledger is slightly cheaper and supports different alt coins, both have different GUIs, apart from that I guess it's mostly a matter of personal preference. Both are known to be secure and have a very good reputation.