As far as I know there won't be any gamecards. I've had trouble in the past with the 'prepaid' Visa cards. They may, however, have changed the restrictions on that from back in the FFXI days (anyone remember that fiasco?). My BEST advice to you is, if you are 18 or over, get an American Express BlueBird card. Everywhere you go it reads as a major credit card even though it's prepaid (Source: I work for AMEX). If you aren't 18 or over, get your parent to get one and either give it to you or add you as a secondary cardholder (which is free and only takes a second to add subaccounts). You'll get a card in your own name and whenever you need it loaded just take your cash to Walmart and load the sucker. Boom. Done. No worries.
Or try the Visa thing and see how that goes.
Current: FFXIV | EVE Online (again)
Former: FFXI | The Matrix Online (FOREVER!!!) | STO | SW:TOR | EQ2 | WoW | Florensia | RF Online
FFXI :: Valefor :: Dareknight, Darexius
FFXIV :: Valefor :: Dare Knight
EVE Online :: Dare Knight, Hazel Knight, Rex Knight