Can I suggest forgetting the chorus? To my ear it rarely does any favours to an acoustic guitar - unless you can get a fast vibey sound. However, a bass overdrive with a mix control would give you the option of a dirty 'layer' under/alongside the clean sound. Delay is also a worthwhile candidate. I would go for the TC Flashback Delay, as one compact unit gives you everything from clean digital repeats for rhythmic tricks, to murky analog for spooky ambience, plus the tape echo simulation is to die for.