50 feet of 3/4" plumbing at 1000GPH will create almost 25 feet of additional head loss via friction.
Switching from 3/4" up to 1" will cut that added loss down to +8 feet.
Switching to 1.25" will cut that to +2 feet.
Let's use 1" for our example.
In a flow chart you'd look up 1000 GPH on one axis and [the height of your tank above the water source] + [added head loss from friction] on the other axis to see which pump will come closest to doing that.
Let's say the top of your tank is 4' above the water level in the garage. +8 feet makes total head pressure 12 feet, or about 3.6 meters.
1,000 GPH is about 3800 L/h.
Looks up 3800 L/h @ 3.6 meters on your flow chart to select the pump that's closest.