I think looking on ebay for a set might be your best bet if you can't find someone locally with *all* the ones you want. I'd even recommend getting the American release of the trading cards, because they got 196 cards. We only got 100, and were called series 1 - but we never got a second series, or the rest of the cards (which included bios of major, 1st year characters).
If you do look for your missing cards on ebay, BE CAREFUL when buying by number, because the larger US set have different numbers on their cards (due to them having almost twice as many, and in a different order).