Funny, but I use that valve, a Genie 1" sprinkler valve and about 200 feet of 14-2 wire to the same float switch you linked to Graingers. But I use all those cheap transformers that pile up from electronic devices - chargers, what have you, and most are 9 to 14v, but have run that float for 30 years. Those 24 volt valves will open on 8 volts. Also you linked a normally open valve, I think he needs a normally closed one. "pump up" ... and you can find that guy for 45$ if you shop around. He does not need anything on the incoming city water except that 24v valve. I would drop a submersible into the tank and then use a square D low pressure cut off switch for the output up the hill. Why worry about the tank going dry? City looses water pressure? Are you in Iraq?