Welcome to the forums.
If you want to keep the Reference center, you should probably match it with Reference mains so the timbre matches, the Reference folks can fill in the details. I'm enjoying my Heritage HT setup, but I already had a pair of Klipschorns. Heresy's and La Scala's are Heritage, 2 or 3 LS or 2 LS and a Heresy or two would make a nice Heritage 2.1 setup especially since you have a sub.