You can just buy an old cheap laptop with the said characteristics...
I think OP is looking for a more cost-effective solution. Something equally good as a hardware wallet but probably cheaper. he didn't say cheaper, but I am pretty sure that is what he meant. He doesn't own a hardware wallet yet and buying any kind of laptop is a more expensive investment than a hardware wallet.
If OP stored Bitcoin only he could consider generating a paper wallet, but since he has other coins as well, a hardware wallet is the best balance between price, security, and ease of use.