Which is an apt professional hair clipper for haircut purpose at home, amid a taper clipper, and a normal trimmer?

I am looking for an appropriate hair clipper for myself, and I was wondering whether I should go for trimmers, or professional hair clipper as taper clipper! I am looking for an affordable hair clipper, which could be used aptly for cutting hair at home. Moreover, my son is 9 years old now, and I wanted to know if a professional hair clipper would be functional and safe enough to be used over his head! Can some professional hairdresser please advice aptly, whether, which is an apt hair clipper for home amid a taper clipper, and a normal trimmer? I would be thankful to you for an early response!