Hi Alan.

For the hardlines I used the 15mm John Guest Speedfit tubing and fittings. It works the same as the plumbing but is made of blue nylon tube with black fittings.
Super easy to install.
I have a couple of moisture trap regulators on some bits and some unregulated ones. All outlets are pcl xf female.
It is not the cheapest but it is easy to fit and adapt later if you need to.

Ollie