so do those panels have a cover over them? i see some kind of rounded plastic looking thing. If that's the case, that must wreak havoc on their output--I have 1200 watts of panels, and the highest output ive ever seen them give me is around 900 watts. if there is any dirt/debris on them, the power drops quickly--id do some testing and see how much power you're actually getting out of those panels. you might want to try and find a way to replace that cover if you can.
Im also running a midnite cc and 8x t105 batteries with a 24v inverter. its an awesome setup and it runs everything i need easily. i never worry about my power and i can even run my welder for short periods of time!
great idea about running 12v loads in series to make 24v--ive been looking at 24->12v step down converters
do you have plans for a breaker box of some kind? how are you combining your solar panels? I used a rooftop combiner box and a dc load box with 175 amp breaker.
also, have you picked out your battery cables yet?? that's an expensive item that you don't want to skimp on.
Patina enthusiast and professional busman