I just got the final parts in yesterday. I have two versions to make--one for earbuds and one for speakers. The amp board I posted above will only be needed if speakers are being used. If for earbuds, I can put it together at half that size--super tiny form factor. I just need to get on wiring...
@TAguirre here's what I found for the amp with volume control... the mics and speakers should be here in the next couple weeks. It's smaller than I expected, which is awesome! I'm still looking at options for the battery to keep that small as well. I'm pretty excited to see if this will work.