I don't know of any right off the bat but I have to commend you on your selection. I'm currently building my boy a gun , I'm using an Encore so I can start him out with the 22 LR then move up in caliber yet maintain the same "feel" for him , the bigger caliber is gonna be the 250 Ackley improved with a 22" light varmint conture barrel , which is the same conture as the 22LR thats on it now.
The Encore is a great gun for kids to start with cause its light and the stocks are easly modified to fit them and it will allow them to shoot both right and left handed if they haven't figured it out yet.
a little cheaper way to get an Encore would be buy the complete gun in say a 243 which is every bit as good as the 250 with the proper bullets