Glass suction cups
 

Does anyone know a good brand of glass suction cups that can safely handle moving a large tank?

Princess Auto sells for cheap and have weight ratings

you have to be careful with the ones from princess auto as they tend to be stubborn to get a good grip and slip easily. i like the woods power grips as you have an indication of the grip level and if its starting fail. both red coral and marine aquaria have them and rent them out. to buy there about 100$ a piece