As above I chose the Ecoflow Stream Ultra X - 3.84kWh 800w output. This tops up my existing 3kWh solar and 5 kWh battery
It is designed to take 2kW solar through the built in Microinverter, so might limit you slightly, but 2kW solar would charge the battery most sunny days - all in for £2k. Are you hoping to export the surplus?
I have always used enough electricity overnight to justify economy 7, and last year (before the new battery was fitted) I used 65% overnight - hoping for 90% now.
You just need a spur in the garage to install.
Here's my set up in the garage.
View attachment 320346