Instead of paying for the external speakers, my husband salvaged a pair of 6 ohm stereo enclosed speakers from a broken smart TV. Since the raspberry pi has an amp built into the 3.5mm audio jack, I posted on stackexchange how to replace that with an amp suitable for stereo enclosed speakers. Someone kindly replied to my inquiry by recommending this product http://www.mcmelectronics.com/product/28-12812
It comes in pieces, so I will solder it together this weekend. One step closer!!!!