Hello rocky1313,
The Klipsch Heresy original 1s were the first speakers I bought new, unfinished in birch to save some money, around 1980 when I was in college. I had a turntable and a 40 watt/ch Yamaha receiver. That system sounded good to me at the time but it would play much (and I do mean tons) louder than I'd ever want to listen;even drunk and getting into the music on a weekend.
I think 40 watts is overkill and would also suggest a flea powered tube set amp or some other low powered tube amp may be the best match.
However, I think you liking the sound with the Wyred 4 Sound class D amps is the most important thing. I agree with others that cautioned about turning the volume too high with your 500 watt amps capable of doing some damage.
The good news is that it's usually not an amp's volume but its clipping and resulting distortion that will fry a speaker. Good class D amps have very low distortion levels and often clipping sensing circuits that auto shut the amp down when clipping.
I also now use high powered class D monos (1,200 watts/ch but on inefficient 4 ohm Magnepan panels) and would expect your amps to sound good on even highly efficient Heresys. Good class D amps are known for extremely low distortion, dead quiet background noise levels and excellent bass response.
You'll always be able to tell when someone hasn't listened to any good, recent model class D amps when they describe them as bright, brash, harsh or fatiguing.
As many have long known, and you're just discovering, the newer good class D amps also typically have very smooth but still very detailed and dynamic mid-range/treble responses without any traces of brightness or brashness.
I'm glad you're enjoying the sound of your combo class D and Heresy system but I'd still suggest trying out a few tube amps just to confirm which you like best.
Timi
