For a portable power source for your speedlights, use the used Turbo 3 Rechargeable Battery from Quantum Instruments.
This battery works with most shoe-mount and handle-mount flashes, including all Quantum Qflash, T-series, and Trio/Pilot portable flashes. The Turbo 3 has the capacity to provide 1050 full-power flashes for shoe-mount speedlights and 750 flashes for handle-mount units.