the 6EX is a very good radio, it has a 10 model memory and 6 channels is plenty for flaps, lights e.t.c,

as for the servos, the standard S3003 or Hitec HS311 servos will be fine for your trainers and sport planes but with bigger planes you may want something a bit stronger/faster or with metal gears to withstand higher loads

the Kadet is a nice plane and i wish you many happy flights!