I wish to install a power shower above the bath the shower head will be only half a metre below the base of the cold water tank.We have a private water supply. A catchment tank supplying a 25 gallon cold water tank so no mains pressure.The hot water is supplied from the Rayburn backboiler to the immersion tank. we would like to install thermostatic bath/shower taps which would be boosted by a power pump. Can we do this in our situation.Or would it be better to install a seperate power shower.