Unfortunately, you are limited to a maximum 10GPM through a 3/4" hose or PVC, so in order to increase that flow, you would need to find a way to increase your delivery method and your hose diameter running to your storage tank. This could be accomplished by increasing the size of the spigot and hose/PVC to a 1-1/4" or even 1-1/2" IF the source can handle that. This could potentially increase your flow rates to a max 26 - 36 GPM, respectively. You could try simply increasing the hose/pvc diameter to 1-1/2" with adapters and use the RJSE-75SS - 17 GPM 3/4 HP Stainless Steel Portable Sprinkler / Transfer Pump . This may get you in that 1000 GPH range.
If you have any other questions, please let me know.