These cards are available in the US in most grocery stores, drug stores and even convenience stores. Most of these cards have to be loaded at the place of purchase and you can’t use a debit or credit card to buy/fund them. It has to be cash only (although I hear that the NetSpend can be funded via PayPal, but I don’t have any way to confirm this)
If you purchase a debit card, you will receive a visa/mc debit card in the mail, depending on which one you buy. Minimum load is $20 and there is a fee attached for just about everything. A $5 monthly fee is attached to the debit cards. The gift cards are usually a predefined amount, and are a one time shot, can’t be reloaded but are cheaper to buy, generally around 3.95 plus the dollar amount purchased.
The gift card I used over Christmas made a point of saying if you use it for purchase online you have to go online and register the gift card with your name/address, otherwise the charge won’t be approved. Anyone who’s purchased online knows the conflicts of a different name/address that on the acct. I don’t know if this holds true for online casinos as well. I just went in and registered the gift card and used it. It might work without doing that, I just don’t know. All together, if I had my druthers as a player, I’d go with the gift card. The prepaid debit card I have gets expensive.