Even with gas heat, that's a lot of A/C you've got there, almost 110A worth on it's own. Did you do a proper load analysis?

I've heard of outside panels in warm places, but the rather "tropical" nature of Louisiana makes me nervous.

I won't screw with 30 circuit panels. What's the point. THe delta for 42 is small and you always have issues with spaces.

There's tons of special circuits that need to be addressed. I recommend you get someone who has a clue about things draw up your electrical plans at least.

You size breakers for the wire, NOT the other way around.

WIre sizes depend on the type of wire, the ampacity required, and the length of the run.

Larger feeders tend to be done with aluminum just for cost practicality. There's no problem with aluminum of feeders/services provided they are installed PROPERLY.

You can wire everything with 12 G (that doesn't need more than 20A) if you like. Makes things more convenient, especially if you've got longer runs.

I did follow up with a licensed electrician in my area that has been nice enough to help me. He agreed with the layout and also said to use the 42 circuit panels as well and pull all of the a/c's out of the first panel even though 2 were in excess of 100' away. He did a load calc. and said 200 amp was fine. He told me to use #1/3 AL SER cable and a 100 amp breaker to feed the subpanel 125' away. Is this adequate or should I up size?

1-1-1-3 AL SER will be fine here (as long as it's three #1 conductors plus the ground).