It depends what you are painting! If you’re looking at smaller models/tabletop minis, you should take a look at setups used in the minipainting communities. Larger models might benefit from different setups. I know I didn’t want to start cheap and have to upgrade later, so I jumped straight for the Iwata HP CS. The dual action is super nice to have (not a must have though). I’d also recommend spending more on a better compressor before a brush (I got a simple 1gal compressor from California Air Tools).
You can self host with Vaultwarden! It’s just the server; you use the same Bitwarden clients.