regarding the AOI units, good idea, makes things simple. Do not go to cheap or it will not work/kill your batteries.
You want to make sure the devices will safely support whatever battery chemistry you will be using.
I mentioned the simple 24-12v downconverter (called buck converter) because you may not need much for the generator and you should get a 24v fridge/freezer as that is going to be your main load. Actually, whatever device is the biggest draw on your system that you want to run directly off the battery pack should probably be the "design driver"; e.g., 24V fridge==24volt system, 12v fridge==12volt system. This makes things easier if you lay it all out and think about the easiest path to your goal.
It is always helpful if you lay out your resources and goals first. It sounds like your "goal" is to have lighting, cold storage, and heat in an easy and cost effective way. Now if your goal is "I want to build a 24V solar system and will shoehorn in other things as needed", well, thats a different goal hehe
take some paper or perhaps your favorite drawing tool and layout your plans with measurements.
add in each physical device and how far apart they may be (longer runs with higher current will need larger guage wires).
so far you have lights, refridgerator/freezer, generator, solar panels (probably want some usb outlets in there for phone/tablets).
Do you have any 120v items that may be big power users?
you then should decide on what connector type you want to use to distribute the DC power and stick with whatever you decide to connect devices to the power bus.
for solar use MC4 cables, the solar standard...
common DC connectors are:
(1)anderson powerpole - they are a bit pricey but a standard for distributing low voltage power; they are crimped and you will probably want to get a powerpole crimp tool; use 45amp connectors/housing for everything for compatibility; you can buy powerpole bus bars with fuses as they are popular in the ham radio community (go on youtube and lookup diy ham radio battery box...sometimes it may make sense to just get a small quite generator and a propane tank for fuel hehe)
(2)amass - XT90 connectors: cheaper than powerpole connector, you solder them(you need a pretty good solder iron), good to 90amps; popular with the remote control model community;10awg; these are single units and the cases are marked with +/- so easy to get right when building
(3)XT150 connectors - barrel connectors that are seperate unlike the xt90's , you need to watch how you solder the female/male connectors and cases so you do not goof it up hehe; flexible, not to costly, handle upto 8awg wire easily so better for longer cables
I would lean towards anderson powerpole connectors and depending on available funds you could just buy prebuilt cables (cheaper to make your own however).
oh.. do NOT buy cheap cable such as aluminum and the most vile.. CCA.. copper clad aluminum, which is often called copper and the CCA tag is in super fine print so they hope you will not notice, sigh...