2 on a 1200 gal cistern, @ pumps?

[Mollymoe]

I have a well with a submersible pump, pumping into a 1200 gal cistern. My neighbor, with whom I share the well and well house, has his submersible pump and water filters installed. I'm ready to install our pump. Our water will have to leave the cistern at a 4% grade going 300 feet (or 15 up in 300). My concern is our larger submersible (because we're up a hill) and his will heat the water (I know slightly, but will). Plus, a catastrophic breakdown could contaminate the water? or not? Repairs with the submersible, more expensive and requires skill sets beyond the backyard mechanic. I like the idea of a nice big stainless steel external pump, keeping the well house warmer, easy to get to, I don't mind priming, and it's not in my drink water.
We will be serving two houses and a barn eventually.
Plus, I want to install a hand pump for emergencies (It [the handpump] has it's port and rebar for a cement extension designed into the cistern lid).
So, is my thinking way off? And anyone have a hand pump recommendation? And the pump for that particular job?

 

[Reach4]

I'm ready to install our pump. Our water will have to leave the cistern at a 4% grade going 300 feet (or 15 up in 300).

Up 15 ft and horizontal through 300 ft of 1.25 inch pipe would not be much. There would be little effect on pump selection.

Where are you envisioning the pressure switch and pressure tank to be? At your house with 300 ft of wire, or at the well house? 3 bath 2 story house? Iron filter? Any unusual water loads, like the 3 acres of irrigation?

A submersible pump will be much more efficient and less problem than a jet pump. If the pump fails, you replace it. No poison in the pump.

Hand pump, for what? Fill a bucket in the pump house, or pressurize the pipe to your house?

 

[Sponsor]

 

[Valveman]

I don't know about Stainless steel, but I would use a J15S pump and PK1A to control it. Grundfos makes stainless, but it is thin wall.
Model JP15 I think.