Since it's too cold to work on my project boat, I am trying to get together the stuff I need for when it warms up. I want to replace the house pump which is an old belt driven thing, to a newer, quieter type. Not sure what gpm and pressure I need or what the old one is. I have 2 faucets and a shower....probably never use more than one at a time. I have been looking at the Shurflo Revolution 4008-101-e65. It's 3.0 gpm and 50 psi pump. I am not looking for a high dollar pump....any other suggestions?