Disney's website states repeatedly that you can use a card rather than a band, so your plan should work (I plan to do the same whenever I return, I did not like wearing the band on my last trip).
But be aware that a few people here have reported having trouble getting the cards at WDW when they've requested them. Some CMs have claimed that they are not available, one person said they were told it would be a big deal to get one for them, and one CM who posted here said that not all resorts still have the means to make the cards.