If you need a power supply that can deliver high currents, try to make it from old ATX PSU. You just need a little modification in front panel like what Peter Sandström did. Here few example uses of this power supply: power source for a 12V car amp, cheap alternative for replacing your broken WLAN access point, flatbed scanner, printer, LCD monitor.
DIY 250W LAB Power Supply Documentation and schematic
Power Supply Source
250W project detail source description