Sewage Ejectors are legal to use in Seattle.
I like the Zoeller brand with a 30" basin.
It comes with a 4/10 hp motor.
2" discharge and 2" vent.
The 2" vent needs to vent through the roof.
You can't use an AAV on a pump system.
This model is a Zoeller 912-0010
In Seattle, they like to see it drained into a 4" waste line.
This pump would handle several bathrooms.