We filter our drinking/cooking water with a multi-stage filter from Culligan. It has a carbon filter and a reverse osmosis filter, and several more specific filter cartridges in series. They know what needs to be filtered in your general area and taylor the specific filters to the pollutants present. The flow rate is good and the company comes out once a year to replace the cartridges at no extra charge. The system comes with a high quality faucet which goes in the spray hole of your sink, or they can drill a hole for it. The system also purifies the water for our ice cube maker. We lease the system for $32/mo. We have it mounted on the wall in the laundry room, but I think it could be squeezed into the space under the sink.