Whole Wheat Flour query

I'm desperately trying not to sound dumb here.....I'm following a recipe for a rye/white sourdough mix that calls for 20% (of total flour) whole wheat flour. Now here in the UK I cant find this, or I'm not looking in the right place? Is it the same as our wholemeal, or what should I be looking for?

Secondly, if I cant find this flour, and for my current experiment, I will need to substitute white bread flour in, I am assuming that I would need to reduce the hydration a little?

Thanks