Gonna sleeve these. Hopefully Dragon Shield or FFG Green.
The cards are 63mm x 88mm, basically MTG size. There are 90 of them: 83 rank + joker cards, 4 reference cards, one tracer card and two alternate Black Hat cards, and if you have the KS edition, there additionally are 9 Celebrity Status cards.
The Black Hat card should be sleeved with a transparent back, since you should always know who has it.
I'm sorry, I don't know Dragon Shield or FFG Green sleeves, so I can't tell you which to get there.