A scope is no problem. You can get a low-price model from Simmons, Bushnell or other makers. Y'all probably have more Chinese-made choices than we have here.
A simple set of rimfire rings, and you're in business. These rifles are grooved for the standard rimfire rings, so no special mounts are needed.
A decent scope should run under forty bucks (or is it 'Roos' down under?).