I wouldn't advise keeping Discus with any species of Geophagus or Angel. The Geophagus will become to large and active for the Discus stressing them, they may also become territorial and aggressive towards them. As for the Angels it is generally a bad idea not to keep them together because both species like to be dominant and territorial disputes and aggression between the two may arise. There is also a parasite which is often carried by the Angels, this parasite does not affect the Angels but does the Discus, so putting the two species together in some cases can transmit this parasite to the Discus.