Do I need a lawyer to sue someone if the amount is more than small claims court alows?

You don't need a lawyer, but then again, you don't need a doctor to give yourself an appendectomy.  It is just a very good idea.  You can also sue in small claims anyway if you are willing to waive the amount in excess of the small claims jurisdictional limit.  If you are not willing to do that, you really should have a lawyer because the rules of procedure and the rules of evidence are both very complex.