Best Used Floorstanders for Rock & HT under $2100?

I already own a pair of Quad ESL63s which are great for listening to classical, chamber and acoustic music, but I also enjoy listening to classic rock and need a speaker with some clear, clean, fast, accurate thump in the lower end to listen to classic rock on. The speakers will also double as the front end of my home theater system. I have a fairly large listening room. I will be using a subwoofer for home theater, but prefer not to have to use one when listening to to 2 channel stereo. Would appreciate any advice on speakers I could purchase for these purposes. Would be great if they are presently or frequently for sale here on the Gon. Thanks.

Bill