Shower install, from Gainsborough to Mixer

[con1_uk]

Hi all,

Pic one is the old Gainsborough shower I am replacing, I have gone back to the stud work and plan to install backer board and wall panels with a new tray etc.

Pic 2 is the new type of shower we would like to fit.

Watching plumber parts videos on YouTube he uses copper piping and a shower valve wall fixing plate but I have flexible plastic pipes, how is the best way to connect the grey pipes with black connectors to a new mixer shower please?

 

[denso13]

New pipe through the wall and use these https://www.toolstation.com/round-bar-valve-fixing-kit/p57883