You might want to check out this site and download the free VSTSynthFont which allows you to load a different soundfount for each midi channel. I don't have much experience with it but have used it in the past to load different drum kits and it works for that.

http://www.synthfont.com/

From their tutorial page http://www.synthfont.com/Tutorial1.html:
"SynthFont is a free tool for playing MIDI files making use of SoundFonts ("SF2" files) or other sound files in formats like DLS, GIGA, 404, GUS. With SynthFont you do not need any particular sound card. In fact, if you only want to render audio files (".WAV" files) you don't even need a sound card. SynthFont makes it easy to assign different SoundFonts to difference MIDI channels."