My son is still in high school and is 18 and got a DWI?

Need to clarify, My son is a good kid. He made a terrible, stupid mistake. He really is a good kid. He is still in High School (because I held him back a year) and he runs cross country track and colleges are interested in him coming to their schools and he has never taken drugs and goes to Church without being told. But yes, he got a DWI on New Years and what I really want to know, is having a Lawyer going to make fines or jail time better than having a public defender?