Questions about Project I have in mind

I am thinking about trying to make something that will be able to play a specific sound file through a small 1.25" diameter speaker (.wav perhaps) depending on input from an accelerometer.

It would have to have a fairly small footprint overall. The width of the board cant be more than 1.25" and the length needs to be less than 4". (not counting the speaker itself or the batteries)

I found this (Arduino Pro Mini 328 - 3.3V/8MHz) part in the store but I’m not really certain if this can do this since I havent worked with these before.

Would that board be capable of interpreting input from an accelerometer (perhaps a Accelerometer Breakout Board - ADXL322 +/-2g) then selecting a specific sound file from some sort of storage device then playing it on the speaker? Ultimately I’d like to play a different sound depending on how quickly the object is moved.

Would it need a OpAmp Breakout to connect to a speaker?