arduino for RFID marked playing cards

I was looking for a project idea, and since I am kinda into magic, I thought about this:

split all playing cards in 2 (technically 3 but you get the point) and place a passive RFID chip inside. then I could connect a vibration motor and an RFID scanner to a small Arduino which I slip into my sleeve. I could then get the values of cards while blindfolded.

these are the problems I am thinking about now:

  1. wich small Arduino would best fit here?
  2. how can I power it with a coin cell battery(or other small battery)?

the whole device would, of course, need to be as small as possible.