Talking about the Kadet Senior you mentioned ARF vs Kit.
The ARF Blue and White has less dihedral and 80" wingspan and Ailerons.

The Kit has more dihedral and comes without Ailerons on the plan. If you are a new plane builder go by the plan or get some help from an experienced builder at your club, its pretty easy to add ailerons to the kit of you know how to reduce the dihdral( nothing to it) and how to set up your ailerons mechanically.