I don't know about your ...

I don't know about your country but here in India, submersible pumps are very cheap. The expenses go up if the manufacturer advises you to purchase stainless steel impeller shaft. In such a case, you should ask the supplier to give you alternate questions (i) for the MOC he recommends (ii) one for the cheapest configuration which is cast iron FG200 impeller, bowl ; seal gland packing; EN8 shaft. Your DTW is 6' dia . Hence, it is best that you do not install pump with dia (bowl) more than 4'. Also you will be able to get a single phase pump for 4" pumps. You require your fields to be irrigated. The rate of pumping can be high or low makes no difference. Arrange for a plastic storage tank at a higher elevation then your field. The staging can very well be made of wood. It is not neccessary to have it of Concrete. Leakage is not the pump's problem. Your neighbour probably did not get quality work from his installation contractor. Ask your supplier that he should do the erection himself and make it a Lump Sum contract. Look at it this way..your aim is to have your fields irrigated and not to have a pump lying at your store. Arrange so that you pay your supplier say 60% only when he shows you that pump is working, your storage reservoir is getting filled up. If it takes 8 hours, let it take.(energy charges have to be low). If you have to irrigate by gravity once every 12 hours, let it fill slowly. If you have a technician known to you who does good work, first show him the leakage in your neighbours piping. Ask him if he can stop the leakage. If he says yes, go and meet your neighbour. He must be a worried man too as he is losing due to the leakage. Tell him that you will stop the leaks at your cost if he agrees to fill your tank once/twicw a day. Share the energy costs in proportion to what you are consuming. Good Luck!