RMAN Backup !

Dear Experts
  Hello !
                   I am working to provide one solution for our testing database Server. I have these following IDEA to implement while taking backup of the Oracle database Server(The service of the oracle can be shutdown if required for the backup implementation).
 
I will take the native backup or using software(ARCServer or Veritas etc ).
 
If I go for  native backup then there are two option,
 
A)  I shutdown the Oracle database service and then take the backup on tapes using tar or other command then start the the oracle  
     service.
B) If I implement RMAN backup then please suggest how to implement the same I hope in this case we do not have to shutdown the Oracle Database Service.
 
 
Secondly If I go with any backup software I have to take the Oracle agent Licence to taken the backup of Oracle.
Now If  I taken only the client(Operating System) License and not the Oracle agent then I have to shutdown the Oracle
service and take complete backup I hope it will work.
 
If i implement RMAN then how to work and we there it will work or not.
 
Now I Implement Oracle_RMAN.
 
Now Consider I am having two Linuix Server,I have install oracle10g  on one Server and configure RMAN for the database backup.
can I implement RMAN in such a way that the backup get redirect on the second box.
 
I hope I have written all my requirement but still any doute please do let me know
 
 
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Thanks and Regards