Any credit card that allows online account access can be a virtual card. Just cutup (or lockup) the card after recording the card information (don't forget the security code) and you have a card that can only be used online and is for all intents and purposes "virtual".
If, by chance, you are looking for a card where you can specify online which bank will pay a seller for your purchase, you are not likely to find anything like that in a credit card. All credit cards are tied to a specific bank that honors them and collects the charges. Sellers are not prepared to collect more information than is on the standard credit card.
The closest you can come to what you may be looking for would be something like PayPal where you can set up several possible sources to pay for purchases and select between them at purchase time. Perhaps some credit card issuers will offer similar services if there is enough demand for it, but I am not aware of any that do now.
