[Mr V]

I'd start by looking at the Delphi Metri-pack series of connectors. Be careful though as you will find a number of connectors that have terminals that will accept up to 12 ga wire but are not rated to carry the full current capacity of a 12ga wire. They are only set up to accept that large gauge wire to prevent voltage drop. Also a given connector has a maximum total amperage capacity that again is not based on the size of the wire that terminals that will fit it are capable of handling. So you may find that 28 position connector that will accept terminals that can handle 40 amps each but not 400 amps that would result from 5 pairs of terminals carrying 40 amps.