I've read quite a few times in this thread to make backups of your bitcoin wallet. But if I'm not completely wrong, then even stealing just the backup data results in losing all your bitcoins. So from a security perspective, better don't make backup copies!

Instead of buying a notebook, I would store a wallet with a fixed amount on a new memory stick. Plug it in only when you intend to pay with it. Don't store more than you could afford to lose on each stick. Delete all backups on computer after using the wallet. And plug it only into computers you know that are clean.