Hi Jill,
I had a filter tap fitted in August I will pm you with phone number and price. It is great not having to carry bottle water up the stairs. I also use this water in the kettle to stop if furring up.
I was talking to a plumber who has an apartment and he said that you have to make sure that the filtered tap water is used regularly as germs could breed in the filter if it is not used. It was all very high teck for me. If not being used for a good while, then maybe just a Brita water jug might be better. The filter under the sink also has to be changed every so many months or after using so many liters of water.
The Filter fitted was called Pure Water KF-EZ-CTO