I would also hook a softner to both your hot and cold water.(too get the full benefits of soft water) as for space look into cabinet models. Home Depot or Lows carries a nice small unit called (The water boss)also very easy to install this is also a Demand softner (this will save alot on salt). These units work very well as long as you don't have alot of Iron in your water . Also install a blowdown filter before the softner this will trap any silt or sediment.