Retired now, but worked in the audio industry for over 20 years, and sold the KG5.5's when they were new. Liked the smaller KG series speakers, actually still have a pair of KG2.2's for a small bedroom system, but didn't care for the larger ones. I think the Heritage line is better, which the Forte is a part of. Also, have a friend that is a Klipsch fanatic, and have heard different models at his house. I had a pair of the original Heresy, and he was so persistent that I sold them to him as he thinks, like some others do, that certain original drivers are superior to the newer ones. If you need it, I have some documentation for the Heritage Series with all the data by serial number from the beginning to 2008.
Obviously, you are looking at used and not sure about your budget, but considering your amp and what you are looking for from the post, my recommendation would be to try this speaker,
http://www.zuaudio.com/preloved/omen-dirty-weekend
They have a 60 day return policy and they pay to return them. The details are here,
http://www.zuaudio.com/questions-list/?category=Commerce
Links to a couple of reviews, and I encourage you to read them carefully because at a glance you may see an adverse comment, but then the reviewer goes further to disagree with that comment.
http://www.positive-feedback.com/Issue66/zu_omen.htm
http://news.cnet.com/8301-13645_3-57591543-47/zu-audios-outrageously-awesome-speaker/
I have a some friends with Zu Audio speakers and have heard a few different models. One in particular that has the Omen worked with me at the last audio dealer before I retired. He made the comment that he would rather listen to his system, than the B&W 802D/McIntosh system at the store, and I definitely agreed with him.
Yes, I do have a pair of Zu's, and no, I am not affiliated with them in any way.