I grabbed the basic toolbox from homedepot: https://images.homedepot-static.com/productImages/b127e2b0-7...
It's essentially destroyed, I've drilled too many holes and generally didn't treat it kindly. I think I will replace it with an identical one now that I have a better understanding of what I'm doing.
Can I ask what case you chose? That was the trickiest part imo.
I went with a hard plastic ammo case from amazon (hard to find in Europe)
If anyone is curious to do this, the youtube videos from Will Prowse are great. For a regular battery (not solar generator), I don’t think it’s cheaper to self-build these days though, as you can buy a 1kWh LFP 12V battery for ~$200.