There isn't a particular laptop that is good for cryptocurrencies I can only advise you which are the best for Linux for example, and my choice is Thinkpad in first place and Dell next because both have excellent firmware support.
So take any laptop and install a distro like Debian or Slackware which are both very stable and secure, but these are for day-to-day use.
While for your cryptocurrencies, buy a USB stick and put Tails in it, which is an excellent operating system that will transform your USB into an excellent tool for your Bitcoins.