That WAU has a sealed tub from what I can see looking at a couple of different versions. You would need the GB? ?? last two digits to be exact. YOu can look upo spare parts for Bosch appliances and explosions on the public Bosch site here as long as you have the full ENR number and the FD number one as well.
I would always go for a 1400 spin washing machine as it does extract quite a bit more water and reduce tumble dryer and line drying time.
Don