I imagine these would sound stupid good with an A-S2100, given the amp's accuracy with piano:
https://www.usaudiomart.com/details/649461306-bosendorfer-vc-7-speakers-with-hornresonator-and-acoustic-soundboards-in-maple-burl-finish/
https://www.usaudiomart.com/details/649461306-bosendorfer-vc-7-speakers-with-hornresonator-and-acoustic-soundboards-in-maple-burl-finish/