Hi Claire,
Any tile you like as long as it not high gloss or polished, you will have an accident. All natural products will need to be sealed and protected and normally have a larger grout joint to help take out any unevenness in the cut. Ceramic tiles are easier to lay and are cheaper bay far, but I have laid tiles of the same batch with a 3mm difference in length!! B&Q for you. Porcelain normally have machine cut edges for the perfect thin grout lines, are harder wearing and for that reason are used in car showrooms, hotels etc, for the best effect. However get the floor as flat as you can and do not be a tight wad on the adhesive!!