What’s your thing with 10" drivers??? Yeesh. That’s a tough ask for a center channel speaker and most likely a bit of overkill, no? But since you asked, by far the best and most dynamic and neutral center channel speaker I’ve ever heard is the ATC C6C. This thing can pin your ears to the sides of your head without strain or distortion. But then it only has two wimpy 9.5" bass drivers, ehem. But as you lament that last 0.5" of missing woofer diameter, the big dome midrange will punch you in the face to reset your focus. And don’t worry about an amp -- it’s active and has discrete internal amps powering each driver for a total of 350 Watts (not sure if it’s available in passive). Not bad for a center speaker, eh? Short of going to some big, hideous pro center speaker, you might have to fire up your workbench to craft something ballsier than this beast. To quote Ferris Bueller, "If you have the means, I highly recommend it." Best of luck.
http://atcloudspeakers.co.uk/hi-fi/loudspeakers/centers/c6c/
http://atcloudspeakers.co.uk/hi-fi/loudspeakers/centers/c6c/