You should consider the new Forte III. Do you have enough room for a third Forte as a center?
My reasoning is that the mid horns in the CWIII and HIII are the older exponential style horns, and to my ears have that horny sound, where the larger format horns in the new FIII do not. (Ditto for the previous FII and Chorus II, if you could find those used you would save a mint).
You should buy from an authorized Klipsch dealer, not directly from them. I recommend
THIS guy. edit: oops, that's his facebook page, but it's still probably the most expeditious way to get in contact with him.
There was a recent thread about another place called Bjorns, which had Heritage on display (at least the FIII, as that was all that was in the pics). I'm not sure if they're in Houston but they are somewhere in the great state of Texas.