Body inflation

Aquarium pumps, brand and gph??

Hi there, I'm looking to get an aquarium pump & try out having continuous gradual flow instead of the manual hand pump I usually use. I've been doing air inflation for quite a bit so I'm not new to it, my issue is... I've bought TWO aquarium pumps this month, and neither were strong enough to use, they also overheat if not submerged. The pumps I bought were 50 gph and 210 gph. I was shocked that buying one 4x as strong still wasn't enough. Should I buy a 1000gph one? Or is there a specific brand/model you guys swear by? I know I've seen a girl use the Tetra Whisper in a video, but I'm unsure if I am safe to get the one for "60-100 Gallon" size tanks, that seems too large but I'm unsure!
7 months