Resisting the urge to suggest that you use the "search" feature, I'll reply anyway...
You can not send ringtones via Bluetooth.
Here is a thread on how to get ringtones to your BB via USB without a data plan. It's a lot of work.
http://www.blackberryforums.com/ring...data-plan.html
I found the thread by searching "ringtone data plan"
A BlackBerry without a data plan is an average phone.