What model to go for?

Hi All!

We recently bought our first house and its a split-level design building. I had a basic router in my appartment and this was always enough to cover everything. The current situation is a bit more challenging since its a 5 story-ish house. 

What would be the better orbi model to go for as i hoped not to spend more then 400 euro's. I do have the option to get a cable backhaul into any floor if needed. Perhaps there are better options i'm not aware of hope you guys can help me out! 

I attached an image of the house layout each floor is about 25m2 (260 sqft) and the stair area is an open area.

Thanks!