I managed to get the Money plant the Snake plant and the Peace lily at my local gardening store. I still need to get the Areca palm somewhere... it is surprisingly hard to find around here.
Growing oxygen in the house
I decided to get some plants that clean the air and provide oxygen. I basically just tried to follow the video here and tried to get the three best plants (Areca palm, Mother-in-Law's Tongue and Money plant.). Also I looked at the NASA Clean air study where they also mention Peace lilies (Spathiphyllum) that also have very good air cleaning capabilities and it also removes ammonia from the air.
So I decided to get Areca Palm, Peace lily, Money plant and Snake plant.