I would prefer Mobile + NFC.
In last Months I try to use my Mobile paying with GooglePay and I am really surprised in how many shops it works. For me its faster to take the phone out from my pocket and pay with.
I guess the payment will not need an internet connection. If the phone will be stolen, no one can pay with it because it is locked and encrypted... NFC cards are not secured in that way, so they have to be locked using a phone service.
I also think most ppl knowing crypto have NFC phones compared to non crypto friends.
Make a poll for that!