I wouldn't waste my time with Click2Pay or ClickandBuy and any of the other small e-wallets.
For gambling, you need to offer cards, Moneybookers (Skrill), Neteller, and one of the big prepaid vouchers - Ukash or Paysafecard. If you also have some form of instant bank payment it'll help with certain countries. If you have that, you cover all of Europe and much of the rest of the world.