Wooden Wainscoting/tongue and groove wall panelling.

I would use a water based satinwood finish in dulux trade and recommend using www.brewers.co.uk

first of all it depends on what finish would you prefer, for shiny you can use gloss, for mid-sheen you can use satin or for something less sheen than satin you can use eggshell. secondly you can choose between solvent based and water based paint, solvent based it will yellow sooner or later but it's got better coverage (1 coat would be enough), water based paint it won't yellow but it will need 2 coats for a good coverage. hope this helps.