Seat cushions with pressure sensors

For a project I have to make a chair where sensors in the seat cushions discover wether a person sitting on it is leaning forwards, backwards, left or right.
I think I'm going to try test it with conductive foam, where the seat area is split in four. Do you guys think this is the right solution....or? If yes where do I buy this conductive foam (I am from Denmark)?

I suppose it would work:

My first thought would be 4 load cells, like the Wii Balance board

Thank you. Yes load cells is not needed in our project. So we go for conductive foam.