Problem with MIDI tunes are that they don't sound same on all handset(of different make). So MP3 tunes should do the trick to some extent, but don't expect miracle. Try MI2 or Mortal Combat tunes. Usually they are loud.
And about battery 8 hours is too short. What do you do with your phone? If you talk on it too much use GPRS continuously then none can help you. But if battery drains without any reason then something is wrong with it. Check it at a Service Center. And also follow the solution given by Pathik to see if it works for you.