Using MIDI instruments in MAX

Hey all:

I'd like to use MIDI instrument libraries (specifically the free ones that come with GarageBand) but can't figure out if it's possible to trigger those sounds without another program.

I can trigger MIDI data, send note on and offs, etc with no problem, so all I can't figure out is how to access those instruments.

Is there an object that hosts instrument libraries and allows me to trigger sounds? If not, should I use SoundFlower to route audio into Max before I send it out?

Thanks!
Jeff