Oxygen 8 And Finale 2003, How do i set it up?? Options

Hello all - I am using an Ibook laptop with a G3, 900 mhz and 640 ram. I am trying to set up Finale with the Oxygen 8. I need to hear what I am doing when I write, so I downloaded a free software syth - Simplesynth 0.7. When I open that program it works, the Oxygen 8 triggers the Quicktime sounds. When I configure OMS, sometimes it recognizes the midi in, but never plays any sounds. Can someone help me set this up? The bottom line - what I want to do...
Arrange on the road...open finale, use the oxygen 8 to trigger sounds and input the music. General midi sounds are fine, nothing fancy needed. Can you help me?

Thanks in advance!
Chris