IF your candidates are under the age of 12, then the artsy-craftsy thing will work in banners, AKA pew markers, with their Confirmation names and hte family name. You don’t need a kit. You need blackline copies, straight pins, markers, fabric paint pens, newspaper to protect surfaces- and time.
I would be hesitant to do this for kids in the 13-18 age group. They have a lot of stuff going on, and you might get flack from those who are less than artistic. You might also get, “That’s what I want” to some signs and symbols that are less than appropriate.
For adults: If I were an adult being confirmed, I’d take mine over to our tailor with a drawing and let her do it.
And in our diocese, we have the same restrictions on stoles and sashes as puzzleannie’s.
Most parishes do this for First Communion, cutting out the felt background and having somebody stitch the top to hold a drinking straw or thin dowel rod. The blanks are then sent home to be prepared by the families with the child. I think this is a good way to do it, as it gets the family into at least disucssing the symbols, if not the sacrament at hand.