I will donate a bottle (or price of) of South African 'champagne' (we're not allowed to call it that) or Catalan Cava.
Nederburg Premiere Cuvee Sparkling Brut SA Wines Online
Pongracz is also good but only available by the case on Amazon
Pongrácz Brut Method Cap classique Sparkling Wine NV 75 cl (Case of 6): Amazon.co.uk: Grocery