Arctic Fox inverter instead of generator?

I had the same situation but chose not to install the inverter there. The DC cables are usually not very large from battery to genset compartment as the expected currents are <30 A typically. 30A will only operate a 300 watt inverter, and probably with significant voltage loss. The first step in evaluating this is to sum up the AC load you expect, pick an inverter, size the cables according to the inverter install manual, then compare to what you have already in place.

A smallish inverter is 600 watts, and will require #2 cable if they are very short - a couple of feet.