I'm not up on what is available in ARFs or even some of the kits today but if you like the 4* then you would like the Super Sportster too. I used the SS for teaching kit building some years ago, very nice plane. Then I changed over to the 4*60 kits. Both are nice planes, I have built too many 4*s now so next student I get I will try to go back to the SS. The SS is a bit harder to fly but is a much better stunt trainer.
Another good choice would be any of the Sticks.
I'm a big fan of the Up-Roars, they come in kit and ARF. The Dazzler is about the same plane but looks a lot nicer with the turtle deck and sleeker controls.
The Easy Sport is a sholder wing plane that a few years back was used for peoples second plane after there trainer. Very stable plane and not a bad little stunt plane.
An all time favorite is the Kaos. Not a second plane for most people but the little 40 size with trike gear is easy to control on the ground and can be a great stunt trainer depending on how you set up the controls.
Just look around for any plane that you like in the 40 size and it will be a good match up for your engine. Your OS is a very good engine by the way.