First, are you miking the acoustic guitar? Spend some time listening to how the guitar sounds in the room and try positioning the mic to capture the best sound. Then don't overdo the effects. Try to get the best sounding signal recorded first without adding a bunch of effects. If your guitar also has a pickup, try recording using it on one track and the mic on another, then blend the two. Also, if you have two mics, you could use stereo miking techniques to capture a better sound.
I don't know much about Firehouse, or how their music sounds, but you should be able to get a more upfront sound by working with the miking and not going overboard with the effects.
