Did you ever found solution for this...i am also facing same issue...one of our database is Oracle 8i...Out app server migrated to WebLogic 10.3, WebLogic 10.3 is not allowing to create Data Source.
Please let me know you’re finding...I greatly appreciate your help....
Most probably WLS 10.3 may not support Oracle 8.x any more. This could be the reason. It may work, I am not sure. But it is not supported as per this link:
May be for your Oracle, you can use Oracle Drivers. But Weblogic Wrapper Oracle Drivers seems to be not supporting oracle 8.x any more.