Maybe someone has a card available for you, I don't, sorry.
But looks like this shop is still selling them for a reasonable price, most stores don't have them in stock:
128MB SmartMedia Card SM Memory 128M SMC Smart Media Cards 128 MB
www.kdavidvolk.com
You can also find them on ebay, but those are more expensive it appears.
También está disponible un tarjetero para SMC. Cinco unidades disponibles que c ontienen emuladores y otro software para la consola. 1- Pérdida del envío por agencia transportista (sólo para envío certificado).
www.ebay.com