Pastor,

Check out the Roland Discover 5M stats here:
http://www.midi247.com/products/roland_discover_5m.htm

Stand alone MIDI file players are hard to find these days. The 5M is probably what you're looking for, but I am not sure if it's available any longer. You may have to settle for a keyboard with sounds that would be sufficient for authentic music playback. I trust you will find what's best for your ministry.

Tim