I tend to use the fx soundboard from adafruit and trigger things from momentary push button switches. The more common approach has been to wire in tactile switches in to the glove finger tips or use an accelerometer or mercury switch to trigger sounds based on specific movements.
I am currently redoing the left portion of my backpack to more closely resemble the avp:r pack. Unfortunately lowering weight and screen accuracy seems to be mutually exclusive when you have to sculpt and form with bondo and resin.
I use an fx sound board for audio triggering and sound playback. I then have the sound output amped to 100 watts on a single pro grade speaker. The only issue I see with that setup is that the sdcard could fall out. Otherwise looks like a good unit on the dfplayer mini module.