We need a new well to replace our old hand drilled 1 1/4" well which is located in our dirt floor basement.The new well to be drilled will be 60ft/4" submersable pump outside well.Estimates vary depending on steel pipe or PVC,which one is best? What HP of pump should we use keeping in mind that we will want to irrigate some garden plots on our 15 acre farm in W.Michigan? How many GPM'S should we shoot for? Thank you in advance for your insight!!!