Do I need invitation letter from China if we go to China for medical treatment?

My name is Princess Kemi Oshodi,I'm the CEO of La-Royale Events in Lagos. My husband have a high blood pressure and we understand Chinese has traditional medicine to cure this,we want to take opportunity of his annual leave in August to do this,now my question is will it be possible for us to obtain visa if we apply now.Secondly I will also use the opportunity to phurchase my catering equipment, for this reasons must we have an invitation letter for this as well/Please I will appreciate your reply.Regards.