Long weekend - lots of work done:
Mounted the computer block and the dc-dc adapter:
Soldered and wired up the harness. Notice the spade connector y-splitters - the radio will be mounted externally and needs its own ground/batt/acc:
I'm mildly worried about having so many splitters on ground/batt/acc - there is a 2 way splitter outside of the box (for radio and box) and 3 way splitter inside the box (amp/computer/monitor). However, none of the components need that much power so I'm not too worried about overloading the wires.
I'm still waiting for the amp to arrive - it will (hopefully) go between to the left of the computer, below the dc-dc. That way, it's right next to the speaker connector
EDIT: I think I might have resolder the connectors on the dc-dc to face up instead of to the sides - it's pretty long and i dont think there's enough space for the wires. There might be enough on the IN end, since the connectors can go outside the box, but on the OUT end, the monitor PCB might get in the way. I've looked at the connectors and it looks like a pretty easy job