You're looking for a connector that you can mount on the side of the box (a "bulkhead" connector), right?
How many terminals and how many amps are you looking at?
Exactly. The I've checked the larger vendors that I'm aware of, and the product I linked to above is the only one I've found for bulkheads.
Maybe 10 connectors would be enough, but the idea is to build this thing so that I don't have to dork with it too much in the future. I would rather over build it now and never use the capacity...
It would be nice if I could run an automotive cooling fan with it... 40-50 amp / 12v would be the most I would put through it. most everything else would be 5-10v sensors, low current.