Redundant Credit Card Processing Solution?

RokaMoka asks: "As I type this, I'm on hold with Verisign Payment Services, our (only) merchant services provider. I run several e-commerce sites, and how shall I say... 'tis the season. At the moment, VPS is totally down, and I am losing thousands of dollars per hour. Does anyone have any experience in designing and supporting e-commerce solutions with multiple vendors for CC processing? What other networks are out there, and what has been the customer experience with them? What should the strategy be, load-balance or fail-over?"