Hello Celeste,
It is possible to send questionnaires manually to suppliers that already exists in SAP SRM, but you must use SURVEY transaction and create your own questionnaire.
Then, in the target hierarchy assign the Recipients or Recipient groups and send via button SEND QUESTIONNAIRES in the same window.
Also, you have some ABAP and Portal Roles for survey creation availables in SAP SRM, all functionalities are available in both.
Hope it helps.
Regards
SG