help me decide speakers for two channel audio

SLightly below your price range are the Avalon Eidolon Diamonds. I think they outperform all but the Egglestonworks.

Used MAGICO!!

Narrowed it down to three.
(1) Wilson audio sophia 2
(2) 802 Nautilus
(3) Usher 8871!!
Please guide me towards one.

I would vote for the Wilsons. More forgiving and musical than the other two, IMHO (I'm not a big fan of Ushers). Of course, that's my preference; not knowing your musical preferences, room size, or what you're really after in speakers, as some of the others have pointed out, this is just a shot in the dark and reflects my musical tastes, not necessarily yours. I strongly suggest you get out and listen to the speakers before you buy.

Would you have room for a pair of Magnepan 20.7s, or some 3.7s plus compact sealed subwoofers?

Otherwise, given this thread's candidates so far, I lean toward the Wilson Sophias too. They're compact, near full-range, pretty coherent in presentation, and have an ease of presentation that allows the music to come to you, i.e., you don't have to strain to catch it.