how would I go about finding visa sub class number & date visa granted,for myself & wife.
Apologies for the delay in responding. Have you tried contacting the Department of Immigration and Citizenship? A list of telephone numbers can be found on their website at: http://www.immi.gov.au/contacts/telephone.htm. You should be able to request information about yourself and your wife should be able to ask about herself.
The National Archives holds migrant selection documents for people who came to Australia on assisted migration schemes. If you came on one of those schemes before 1981, we may have a record relating to your application process. Also, if you have been/were naturalised before 1981, we may have a record relating to your naturalisation. If you think we may have records relating to you, you should submit a reference inquiry at http://naa.gov.au/collection/forms/imm-inquiry.aspx
Records after 1981 are currently not in the open access period, and therefore not publicly accessible. For more information see http://naa.gov.au/collection/fact-sheets/fs10.aspx.