Very nice amp. You'll have no problems driving just about anything out there. So suggesting something would be difficult as all speakers sound different and what sounds good to us, may not sound good to you.
So lets start here. What was it you liked or disliked about the Synch 2's you had? Did you listen to all the above on your list and did any remind you of your old speakers? Were any opposite?
I prefer soft domes and tend to gravitate toward speakers using this type of driver. I have heard the Liuto and it is a very nice speaker. It also uses a soft tweeter and I wasn't surprised that I enjoyed them. Also, if you can get them new at or below your budget, thats a great price too.
If you liked the way it sounded, then I would suggest you also consider and audition these - Vienna Acoustics Mozart Grand SE and Dynaudio Excite 36. They are in your budget and you'll have no trouble driving them. I hope you get many more suggestions in your journey to find the speakers that sounds best to you.