Bière de Garde

Does anybody know where I can get my hands on some Trois Monts in London? Since reading about French farmhouse ales in Garrett Oliver's "Brewmaster's Table", I have been on a mission to seek it out to no avail. I have some Saison Dupont to take care of my Belgian farmhouse needs, but have had no luck on the French side. In my search I did luck across a whole stack of other gems at Whole Foods, Kensington - I will elaborate further upon these in the future. For now I have my sights on 3 Monts.