Selecting a drilling pump can indeed be challenging. It's essential to consider several key factors. First, the type of pump is crucial. Piston pumps are typically more powerful, while diaphragm pumps are valued for their simplicity and reliability. Screw pumps are known for their efficiency and consistent flow, but they may require more maintenance. Additionally, pay attention to the pump’s capacity and pressure, as these are critical parameters. The pump's performance should align with your drilling requirements, and the pressure must be adequate to ensure a stable drilling process, especially at greater depths. For manufacturers, I recommend checking out BORG
https://borgpumps.com/. They offer a wide selection of equipment, and their pumps have a solid reputation for reliability and durability.