don't worry too much about matching the 1100 gph like on the Gold Cube 12v pump. I went to Harbor Freight and bought a submersible 110v pump and I believe was somewhere around 1600gph? It works excellent. no excuses the Cube can handle more water volume. When i run the trommel option or run in the field i use a 2000gph 12v Bilge pump from Amazon - 39.99 for the generic brand and works perfectly.
I just looked up the pump at Harbor Frieght is 1/6hp Submersible Utility Pump 1600gph is listed online for 64.99. you will not be disappointed. you may need a barbed fitting as i had to get. I went to the Tropical fish store across from my Harbor Freight and they had a fitting with the correct nipple to fit the hose. Just ask at the counter as the parts they have are usually behind the counter and you have to ask for them. Amazon has them too for about 7.99 - best of luck.

As long as you find a 110v pump between 12 and 25 GPM (per minute) or 750 and 1500 GPH you are good. An easy way to not run out of battery in the garage is just hook it up to batter hooked to the charger. That way there is nothing more to buy. We now have the barbed fitting on our web site in both the 3/4" pipe and 1" pipe thread to 1-1/8" barbed fitting. https://goldcube.net/product/barbed-fitting-3-4-x-1-1-8/
Mike