Advice on cabling, packaging and connectors for 12v light project
generic DC connector advice:

avoid the use of connectors which connect serially, like headphone jacks. you make strange combinations while plugging in

avoid connectors which do not latch, like headphone jacks

in a system like yours, with stages and signal processing in between, use different connectors for each phase, so you can not get it wrong

use connectors that can not be connected backwards for DC. I prefer:

Hopkins 47965 2-Pole Flat Extension for raw solar power.Not because    it's a great connector, but because it's common in low power solar


Anderson Power Poles for regulated DC power. you can secure them
together with a tie wrap; you can't connect them backwards without
doing things that are obviously counter intuitive.
Fuel injection    connectors from Autozone for signal wires. they got
a million of    them, they are made for DC at useful current levels
Trailer    connectors for multiple lead serious power.
XLR connectors can be    found from 3 to 6 pins, and you can't jam a
5 pin into a 6 pin, so    you can't cross connnect


keep things dummy proof.