(My debit card is much less convenient because some new attack happens at least once a year where they have to send out a new card.)
Alternatively, check with your bank and see if they have a bill-pay service.
However, even at banks with good policies, "extra" security measures are excluded from Zero Fraud Liability. PIN transactions, Verified by Visa, etc. appeal to the HN spirit of "taking responsibility" for your own security. But you are doing just that - "taking responsibility." If the added layer of protection can be broken (hint: it can) then you will have no recourse. For a credit card, your loss is at least capped at your credit limit; some debit cards have transaction limits of $15k+. We're talking possibly your entire account, irrecoverable, because you were an idiot and tried to protect yourself instead of letting the rest of the system eat the loss.
The security of your credit card number is everyone else's problem. Treating it like your own problem is actively sabotaging your ability to recover from the inevitable fraud.
(I know you can obtain pre-paid cards in large increments, but that doesn't really help here.)