How can you defend a drug conspiracy charge verses a possession or distribution charge?:
You shouldn't expect to get a realistic answer from anyone here because no one here (except you, perhaps), knows all the details of your case.  It would take an attorney no small amount of time to prepare a defense for you, and nobody here is going to be able to offer you real help without knowing all the details.  This is one of those situations where Y!A really isn't going to be especially beneficial for you.