Zoom A2 is a great little acoustic unit, I use mine to jam with friends and play the odd gig with. The reverbs are very good and the A2.1 has a semi decent USB interface to record through and expression pedal.
Pod's are mostly for electrics but the new X3's have Bass, vocals and acoustic settings. As for whammy my latest recording uses the pedal of the pod to create a vibrato/tremolo effect, it sounds ok and its easier to use than the whammy on the guitar. There are other rotary, dual tones setting you can do.
Hear for yourself.
Rooster Rules The Roost