The Viewpoint resort is very nice and quiet as its about a 15 min walk from the centre of Tonsai village. However, it's a steep uphill slog to the cheaper bungalows (fan only) so the most kid friendly option would be to get one of the fancy ones with TV and air con. They are right next to the office and dining room.
It's about a 15-20 min walk from the Viewpoint resort to Tonsai Tower.
If you stay in town you get the very southern Thai combination of thudding music from the nightclubs til the wee small hours, then the call to the faithful from the mosque at the crack of dawn. (BTW: The chao Phi Phi are very proud of their mosque and would love to show you through it.)