I recently found a 4" well casing on my property in northwest Illinois. With some investigation from neighbors I found that there used to be a farm house and store in the 1920's using this well. The house and store have been gone for at least 40-50 years. The casing was capped with a coffee can and it measured 60 ft to the bottom. There is 30 ft of water in it. I dropped in a 16GPM submersible and sucked it dry in 2 minutes. After I wait 10 seconds it will pump again for about 20 seconds. So on and so forth.
My question is,
I would like to purchase a 7GPM for an apartment I am building on the site, is this still too much pump for this well?
I will be pushing the water about 400ft to the apartment, what HP do I need?
One more question, if I am running wire to this pump from my service entrance, what gauge should I use? Its about 400-450 ft to the pump motor to the electric service.

I really appreciate any help you may offer