I wouldn't suggest a Cub for your second plane, this model is difficult to take off and land, and you need to perform perfect coordinated turns up in the air or just try to.
I think you still need to learn how to handle taildraggers, a different model is to be choosen, of course building it as a second kit would be fun and doable, but I am not sure that will be what you want to fly as a second plane.