There are two types of popular aeroponics systems and they're based on the pump size. Low pressure system can use very inexpensive pumps - pumps usually sold for backyard ponds, for example. These are often used in basic DIY systems. They're well suited to an aeroponics setup if budget is a concern, since those pumps are cheap and easy to find. Pond pumps are rated by their flow rate, in GPH, whereas high pressure pumps are rated by PSI, making them difficult to compare.
High pressure systems, on the other hand, require more powerful pumps, such as diaphragm pumps or reverse osmosis booster pumps. They're more expensive, but they usually need to produce a steady 80 PSI at whatever flow rate you require. These more powerful pumps can produce the ideal droplet size of under 50 microns, which allow for more efficient nutrient uptake by the roots.
