here http://www.rivergatedist.com/PowerSupply.htm
I personally carry one of these around with me:
APS55
740 Watt

Cost: $278.40
Cost with IQ4 module internal: $327.90
Warranty: 3 year

Power Supply Features:
- Switching Power Supply
- Full Output at all Times
- Marine Ready
- Only Two Different Case Sizes
- The Professionals Choice Worldwide

Download FAQ Sheet
PART: APS55
Dimensions: 7.5" x 6.5" x 3.5"

http://www.cascadeaudio.com/power_co...converters.htm