What do I use with a shower with a plastic pipe connection to join it to a usual domestic copper supply pipe?
First off ,read the paperwork that came with the shower.Most new showers come with plastic fittings inside and they usually state that you must not use speed-fit plastic fittings on them.Normally you would connect it using a standard compression fitting of the correct size.In the UK that would be a 15mm brass compression fitting.The plastic pipe in the shower is engineered to be connected by using a compression fitting so don’t worry about crushing it. Also,if its an electric shower,check that the supply cable is the correct size for the shower rating bearing in mind the distance from the distribution board.Unless you are experienced in this it is usually safer to replace like with like.Be aware that in the UK all new showers are supposed to be protected by an RCD and because of their location are now subject to part P testing.
