There is a Sportster in the EE right now, only in 17HMR. These rifles have been out of production for some time, so you may have to search around a bit. They do pop-up in the EE from time to time. I'm not THAT old, but even I remember seeing these @ Le Baron for $150 new, seems asking prices are significantly higher these days. Only think that has steered me away from them is how heavy the trigger is. At the time, I couldn't find any evidence of people successfully improving the triggers on these.
I believe Rossi makes a single-shot/break barrel .22 but I know almost nothing about the brand.