Unfortunately, the market is somewhat bifurcated between what Anker, Jackery, Ecopower provide and stepping up to Base Power, Powerwalls, and other bigger system components.

My recommendation would be to see if Ecopower storage and inverters are a good fit for your use case. If you're feeling adventurous, you could build your own battery pack, but I only recommend if you are knowledgeable and confident. This comes with substantial property and life safety risk, only proceed if you know what you're doing and understand the risk (I'll work on my high voltage EV battery packs, but only with a helper nearby holding a 2x4, for example).

https://hackaday.com/tag/battery-pack/