If I may throw in some thoughts..

Soundfonts are a Creative Labs innovation and so are intimately linked with the Audigy and previous creative soundcards.

Therefore to play SoundFonts, the easiest way is to use the Audigy... but if this doenst co-exist with the Aadvark then you may be between a rock and a hard place.

Theres an interesting interview about soundfonds here: http://www.soundfont.com/guzewicz.html
which suggests the possibiloty of third-party software synths that could use SoundFonts.

Thinking about it, commercial sample playback software might do the job e.g. http://www.guitar-zone.com/keyboards/s/Samplers_Playback_software/BitHeadz_Unity_Sessi_704136.htm

This also looks interesting: http://www.hitsquad.com/smm/programs/bs1_win/