Not positive on the new ones, but the old ones could use MIDI files as ringtones. you had to go to a url with the midi file and then save it into the phone. once there, you could select it as a ringtone. I gave up my bberry a year ago - after 5 years. Was sick of being tethered to email - so I don't have one in front of me to try it again.
Anyone who has problems with the downloads can contact Xingtone's support at http://xingtone.com/support/contactSupport.htm If the live help is down, send me a PM.
Also....Verizon is touch and go about phones being supported. See the help page on the website listed to which Verizon phones are supported.