You will need:
2x Clamps to fit your handle bars (mine were 1 1/4" availiable on line for ~$10 from ebay)
1x Optronics QH-87CD 2 1/2" high performance Halogen driving light kit ($15 at Walmart)
2x 2" mid to full range speakers. Highter the RMS wattage the better.
(Partsexpress Tang Band W2-803SM $32.64)
4x 1" metal washers (Home Depot or Lows ~$2
Small peace of screen door
Wire and switch (can use parts from Halogen kit)
Also you may want
Mini amplifier (Ebay 500w for $18 shipped)
1/8" male phono to stereo rca type cable to plug audio source in to amp.