Yes, I would have to send them back to the factory to convert them to stereo amps. From what I understand, internally bridged factory monos are the way to go for ultimate performance. I do not like the idea of extra cabling with the Y-adapters. The more connections, the worse the sound. Why spend that kind of money and not get them configured as monos from the start. Of course, if you think you might want to biamp (with multiple preamp outputs) then by all means get the stereo amps and use multiple interconnects. I would prefer multiple preamp outputs and interconnects to using Y-adapters. My personal preference.
Joe,
Have you got your monos yet? If so, I'm sure we all here would love to get some initial impressions from you.