Just cuz I added more onto an already full plate of choices
Ushers are an interesting case because in your price range they don't really have any tower speakers. There are the S-520s plus Bass Stands which in effect creates a truly fullrange 3-way speaker (crossover at 200hz) but I don't think anyone here has actually heard the S-520s with bass stands. The Mini dancer comes in at $4000 MSRP OTOH
Marantz, Denon, and Yamaha are all great right now. I would personally look into the Denon 4311CI and pair it with a two or three-channel amp but really it's not necessarily necessary. I would lean towards a marantz SR5005 on that note as the auto-EQ on the SR6003 gave me good results but past that the speakers and the room give you the sound, the receiver gives you the EQ, amplification, and management. Some prefer the sound of source direct mode anyways at which point even room EQ is useless. I personally had better results with the more lively audessey flat for music and don't mind audessey for movies. I think my speakers in my somewhat dead room end up too dark and distant without room EQ.
Of course Room EQ is no excuse for paying real attention to your room. The room is a huge part of the sound you hear so you should budget a good deal towards getting controlled late reflections and minimal early reflections among other things. You'll find this especially helps at louder listening volumes where reflections are more harsh.
Regarding sufficient amplification, that will depend on your final choice in speakers. Some speakers are perfectly happy being driven by a 100 dollar sony and other speakers will require a separate amp costing half of their own value to be properly driven. Your best bet is always to buy speakers for which an impedance/impedance phase/sensitivity graph is readily available. Never trust a nominal impedance rating. There's some nominal 8 ohm paradigm speakers that dip to like 3 ohms for example.