From experience whats the best puppy to get with a 4yr old?

we want something jack russel size but apparently there really snappy what about staffies or king charles id like the type of dog thats going to be playful but not yappy that will snuggle down at night but were in a small house so not 2 big but we have the biggest garden and are in the countryside so its got plenty of room to exersise a loyal loving dog