Put them in a Family, add a Family instance variable ID, and for each Sprite type have a different ID (1, 2, etc), and check the pressed one's ID is the same as the displayed one. I think that will work.
[attachment=1:2xnxe8zr][/attachment:2xnxe8zr]
edit: after doing this I thought you might just use the Nickname plugin..
2 families, a little more setup (2 lines per object) but scales better
[attachment=0:2xnxe8zr][/attachment:2xnxe8zr]