Alternatives to breadboards for high-current applications
If you just need to work fast, I recommend a peice of 1/4" plywood as a project surface.  Get a variety of lengths and sizes of wood screw and screw a breadboard, some screw terminal strips, heat sinks, electrical boxes, power supplies, etc (hereinafter Resources) to it.  Don't overthink the layout, just make sure it's big enough and has enough Resources.  You can fit a lot of stuff into 18"x18".  What you're trying to do is create a work area where you're not plagued by bad connections, congestion, and missing Resources.

You should be concerned with fire when working with high currents.  Just make sure you can easily disconnect power and keep a working fire extinguisher nearby.  

Plywood is flammable.  You could use metal but metal is worse in almost every way for this purpose other than flammability.  There's usually lots of stuff that can catch fire on a workbench, so you need to heat sink the hot chips properly anyway.