The pumps will be ideal for large ponds. You would want to circulate the water 1 1/2 to 2 times per hour in a pond over 5000 gallons. Circulating the water will help keep a good amount of air circulation moving as well as keep your pond filtration working well.
The maximum pumping height (head height) is the height a pump will raise water straight up resulting in zero GPH of water flow at the top. As the height of any pump discharge increases, the flow will decrease. Head Height is especially taken into effect in ponds this size because of tubing location restrictions. Example, where a waterfall may be located in reference to the pump location.
To calculate head height:
Every 10ft of horizontal tubing = 1 head
Every 1ft vertically = 1 head
Every elbow = 1 head