the BitFenix Prodigy will fit any standard ATX size PSU, so just pick a decent quality one. I always see the XFX or Seasonic ones being recommended on this forum
Power Supply:XFX 550W 80+ Bronze Certified ATX Power Supply ($59.99 @ NCIX US) Total: $59.99 (Prices include shipping, taxes, and discounts when available.) (Generated by PCPartPicker 2014-05-02 19:55 EDT-0400)
OR
Gold Certified \ FULL Modular \ Seasonic made \ Best 550 watt on the market.