Rega Brio R or Alex R for new Klipsch Heresy III's.

Despite the high sensitivity of Klipsch Heresys, which I have owned for nearly 40 years, I learned while working with LaScalas (18 years), that the short throw woofers of Klipsch speaker benefit from as much power as you can give them.  That is why they synergize well with McIntosh amps.  I think your choice of Rega is a very good one because of their musical and non analytic  house sound.  Go for the power you won't be sorry, I assure you.
Yes you can get them playing loudly with a 3 watt amp but the sound is usually dominated by their powerful midrange horns. The added power gives the woofers a chance to be heard.

Very interesting info. mechans. Most appreciated....

You might consider the Heed Elixir.  I auditioned one this weekend and the Peachtree I mentioned earlier in the thread is going bye-bye.  It's a simple integrated - 50 WPC Class A amp, 4 inputs plus a MM phono input, pre-outs, and a Class A headphone amp. It's very similar to the Brio, however in the reviews I read most give a nod to the Elixir.  I had never heard of it before, I was visiting one of my favorite shops and they had one.  It really grabbed me and I took one home.  The dealer gave me a 30 day window to return it, but I think it's staying.