card-sized 4 Kbit RSA Smartcard recommendation with 3 slots

[Thomas Glanzmann]

Hello,
I'm looking for a recommendation for a cardsized 4 kbit RSA smartcard
with 3 keyslots which works with Linux und Windows and gnupg. Has anyone
a recommendation. At the moment I use yubikey but I aquired a laptop
with a smartcard reader that I would like to use in order to free up an
USB slot.

Cheers,
        Thomas