Just be a bit careful, if you buy a new toilet with the bidet feature built in, the majority of these are bottom outlet (in other words the waste outlet is in the floor under the foot of the toilet) toilets in the UK are back outlet. With the kits you will be breaking UK water regulations (not that anyone will ever find out) you need to have an air gap between mains water and sanitary system, this is to prevent the possibility of toilet bacteria being able to enter the drinking water supply.