Well you do know that finding synth resources is what this site Synth Zone
is all about. Try checking http://analog.no/
for WAV recordings of the tape patches. All you need to do is run the audio output of your soundcard into the tape in on your Poly-800 and play the WAV file into it. You may have to tweak the output level from the soundcard so the Poly-800 detects it correctly as a tape signal, but it can be done.