As a starting point you may wish to check these two websites out:
http://www.quadesl.org/Amplifiers/AmpList/amplist.html
http://www.geocities.com/[email protected]/
FWIW, I drive my Quad ESL-989s which I believe are each the equivalent of two ESL-63s quite happily with a Conrad-Johnson Premier 140 amp.
Good luck in your search.
Joe
http://www.quadesl.org/Amplifiers/AmpList/amplist.html
http://www.geocities.com/[email protected]/
FWIW, I drive my Quad ESL-989s which I believe are each the equivalent of two ESL-63s quite happily with a Conrad-Johnson Premier 140 amp.
Good luck in your search.
Joe