Dear Jackson, a gestor in Spain has nothing to do with a lawyer, a gestor is basicly someone who carries documents, presenting them to authorities, paying taxes, doing the popular spanish queues, they cannont give legal advice or prepare private contracts.
Only a lawyer can give legal advice, including the advice you need for buying or selling a property, and they have a compulsory insurance to cover their proffesional responsability, big difference with a gestor !.
Beware of spanish gestorias or asesorias, be sure you are using a registered lawyer ( they have to be registered in any of the regional “Colegio de Abogados” or Lawyers official colleges. Only use a gestor or asesor for minor paperwork.