Which Smart Inverter to match with Fogstar battery?

I've got about 4kW of panels and a basic inverter in the loft. I want to get this Fogstar 16kWh battery https://www.fogstar.co.uk/products/fogstar-energy-ip-rated-16-1kwh-48v-solar-battery and a smart inverter that can a) auto-switch the whole house to battery if the grid is down; b) automatically charge at cheap overnight tariffs and using any spare solar power during the day, exporting any that isn't being used by the house or needed for charging; c) work with Home Assistant so I can use it to display data, send notifications, etc.

The consumer unit is in a cupboard under the stairs and the cable from the current inverter comes down the outside wall into the garage and through the wall under the stairs. With the new inverter I'd put that in the garage and run a new cable from the solar panels, bypassing the current inverter so I can remove that from the loft.

Would this Sigenstor 12kw smart hybrid inverter do what I want and work with the Fogstar battery? https://www.itstechnologies.uk/products/sigenergy-sigenstor-12-0kw-smart-hybrid-inverter-ip66?variant=56807197770109

Would I need this Gateway as well?

https://www.itstechnologies.uk/products/sigenergy-sigenstor-gateway-homepro-sp-f-ac-current-100a

I don't have a heatpump yet. If I got one in future I could add extra batteries if necessary but would that 12kw inverter still be sufficient?

Are there any other inverters I could use, other than Tesla, and if so do they all need an extra Gateway unit?

What should I do to minimise the fire risk? I understand that the batteries have a low risk of self-igniting and the main risk comes from the inverter igniting and the fire spreading to the battery? I thought of putting the battery at the end of the garden so that if it does catch fire it will be away from the house but I'd need to dig a trench to bury the cables for that, which would be tricky. Are the cables that run between the inverter and the battery, the solar panels and the gateway/consumer unit all fireproof, so fire can't spread via them? If so, could I put the battery in the other half of the garage nearest the house with the inverter near the garage door to keep them separated, with a fire suppression system over the inverter so if it does ignite the fire will be extinguished before it can spread to the battery?