I would take a serious look / listen to the Spendor D7. This speaker has been reviewed a lot. You don't see it come up on the used market a lot, but it still does on occasion. Would work well with your current amp.
If your looking for an amp down the road I think it would pair up to the Primaluna Dialogue Premium or a Rogue Integrated well (both lines are high value). The speakers are 89-90 sensitivity, rated at a nominal 8 ohms. I have included (below) a link for a pair currently listed on usaudiomart
http://www.usaudiomart.com/details/649299827-spendor-d7/
If your looking for an amp down the road I think it would pair up to the Primaluna Dialogue Premium or a Rogue Integrated well (both lines are high value). The speakers are 89-90 sensitivity, rated at a nominal 8 ohms. I have included (below) a link for a pair currently listed on usaudiomart
http://www.usaudiomart.com/details/649299827-spendor-d7/