With upcoming CBSubs 1.1, 2Checkout support will be added, also on this site.
That said, I've looked at many gateway protocols, and I have to say that Paypal's is today the one which is the safest for the payer and for the site owner.
You may not like Paypal for other reasons, and it's your right, but Paypal's protocol security is really good, if implemented properly, and from many implementations I have looked at, CBSubs one is really thorough security-wise.
You do NOT need to open a paypal account and store your credit-card number there. Just click the "Continue" lnk here when arriving at Paypal.com website:
Don't have a PayPal account?
Use your credit card or bank account (where available). Continue
Then you can just put your credit-card and pay without creating a paypal account.