Here's how I did mine:
I ran power and ground with 8 gauge wires through the firewall and connect to a Blue Sea Grounded Fuse Block to serve as a distribution panel for things that I can run with the engine off (ie: HAM radio, fridge, and Victron DC-DC charger) Everything is bolted down to a custom mount I made with scrap wood and mounted under the driver rear seat, so when the seat is put down no one knows it's there. When I need to service the items (switch fuse, add more things, etc) I simply flip up the seat. There is also a 60A Blue Sea Circuit breaker I put next to the starter battery since this circuit is hotwired to said battery and body grounded in the engine bay.
The Victron DC-DC charger can be both connected at all times or set to be isolated when the IGN is off by connecting a IGN power source and act as a trigger. It is connected to the Blue Sea fused slot due to the power demand that I have for it does not warrant thick input into Victron (I use the Victron to charge my Delta 2, which holds 1000W and used as power source for diesel heater for winter and EcoFlow AC for summer). The input of Victron is no more than 13.5V at peak, and the output is no more than 12.5V, so no need for thick gauged wires.
You can do the same to install your inverter. I'd skip any stock inverter option because it's really weak anyways. Just run power and ground through firewall in the cab, add a breaker at the beginning of the power cable (near battery), and install your inverter there. You can run trigger wire to the IGN controlled fuse slot under the steering wheel as source of power for trigger.