I like the second for being more balanced, but why not run the loads on the first across both pairs instead of having an upstream and a downstream pair? ( I can't remember if you are a balancing believer or not. If not, never mind :) )
Another way is to have twin wires for pos and neg right from the inverter with one set to each pair. Those wires then power the inverter plus act as the parallel links so you don't need to parallel the pairs as well with more wires.
Where do you tap off your 12v and get your 12v ground to the frame for the 12v items that use the frame for neg to battery?