May I suggest you instead of buying new speakers update the Klipsch's. I did some older LaScala's a few years ago and the outcome was very good indeed. I used Bob Crites tweeters and crossovers (specifically the 4500's) this eliminated the bright and harsh top end of the factory tweeters and smoothed out the response. made a huge difference and improved the sound and removed any listening fatigue from the top end.
they have parts for most of the Klipsch horn speakers.