SoundGuy wrote:
Any input on this idea of using the truck (running) as occasional load support to the trailer battery when powering the inverter would be appreciated. :)
Sure, why not ! If you are going to make it a more "permanent" connection instead of just jumper cables, you are going to need 8 gauge or better wire.
Personally, I think AGM batteries are not worth the extra cost. Yes, flooded cell batteries require more maintenance
(check and top of water once a week when in continuous use and outside cleaning).
Other have said it before, the best "bang for the buck" are a pair of 6V GC batteries from Costco.