I think your card looks nice, but I understand about wanting a "variety".
If you can't find the stamp for the greeting you want, print some off your computer and use your punches to give yourself more options.
I have some hockey cards in the "Just Hockey" gallery if that helps. I will be adding more once I find some time.
You might also consider making "packets" for the mom's to buy all the same layout, but with some different sayings.
Or tags - boys don't care about the card, just the gift
Good Luck!