Oracle backup scenario 9i

So, I have problem with backup scenario.

I have 4 servers all under suse linux os and one of them is 24x7 available, other are production servers which work 5 days per week (for weekend servers are not in using). So I would like to make best possible backup scenario using rman tool in Oracle 9i. My startup idea is to make hot backups for all servers using rman (making rman script which will be started every day through cron). But if somebody has better or more creative scenario please let me know.

Thanks in advance

best idea,, rman hot backups