Please excuse the mess, literally halfway through cleaning and repointing

This is the basement brewery, where the new sink will go - the upper section is going to be clad in upvc cleat wall over the sink, the bottom meter or so - well this is the question.

We want to clad it over, what would be the best material? Blueboard? Villa? Cement sheeting? Preferably paintable as the sink is an industrial open base, so we're planning on running exposed copper over it. What size airgap would be needed over the brick? Standard 25mm?

We really don't want this wall exposed, every other wall down there is brick anyway so fuckit.