I say stay with the Heresy's if this is going to be a home theater system primarily. The punch is good for movies, plus if you think about it, the Heresy is probably very similar in design to actual theater speakers...well the JBL professional ones I was looking at (12 or 15" mid-woofer, huge horn tweeter).

I assume Klipsch Heritage line doesn't include a center channel, but do they sell any of those speakers individually? Though if you wanted your center to sit on top of a TV then you obviously would to need to go with something smaller like the RC-35....