What is the depth? What is the yield in litres per hour? Motor manufacturers have a catalog that will specify the depth & yield for each motor. There will be many motors matching your requirement. Depending on your requirement, you choose the motor. Cost will vary depending on no. of stages 3/4/5/6 stages of motor), construction material (steel or stainless steel), material used for impeller (steel or plastic) etc. If you decide on Texmo, go to the dealer. You may consider CRI pump also. 7.5 HP mptor with 4 stage pump would cost around 22,000-23,000.