I was considering 2 CBM-170 for the mains and 1 HTM-200 for the center. My thinking was that the HTM-200 SE would be a better choice since the center channel will be placed inside the credenza and it's not ported. Also that they have 4" woofers which (may or may not?) lend itself to a better mid-range for dialog.
After reading past posts dating back a few years, it seems the way to go is 3 CBM-170 SE across the front. I'll experiment with plugging the port on the rear center channel with some open cell foam (a-la Q-plugs). Thanks.