I'm thinking something like
this, or maybe
this will be enough to ensure I don't have problems. Both of them specifically say they work on all metals (I'm sure that would include aluminum) and protect against ethanol. I'm assuming most of the tank sealers out on the market will work so I'm going to proceed with the tank build and plan on sealing it with one of these.
Now I just need to decide what aftermarket in-tank pump to use.