For budget conscious home theater setups I always recommend Polk speakers, but at over half off Amazon's discount prices I don't think you can come close to their performance for that price! If you have room for the RTI A7, go for them. There are reviews of the RTI A3 that say they have better imaging which is common for a two way bookshelf, but if you are going for big home theater sound and impact I would go with the 7's.
More important, don't skimp on the center channel. The two-way CSi series will get the job done but won't give you the same impact as the mains and you really want big sound from the center channel - that is where the action is in soundtracks most of the time. The Polk CSi A6 would be the minimum I'd recommend but the higher end 3-way LSi center speakers would give you better horizontal dispersion to spread that sweet spot out to all seating positions and give you better voice clarity. Get the top of the line LSiM706c or LSiM704c if you can budget it and have the room.
Most of the small Polk subs are anemic, but that one (especially at that price) would fill the bill with the RTI A7's as mains. As for AVR, with those two brands it is more personal preference. If you were comparing a Sony and a Denon there would be no contest. Any of these are going to be able to drive those speakers, so I would recommend spending more on speakers if there is a budget issue. The AVR is probably going to be the first thing you replace down the road if you buy the right speakers.
2-Ch (HT L/R): Oppo BDP-105 BD, Adcom GFP-750 pre, Bryston 10B Sub Xover, Bryston 4BSST2 / Paradigm Signature S4 v.2 (L/R), (2) SVS SB12-NSD (Subs)
Home Theater: Bryston 4BSST2 amp / Paradigm CC-590 (C), Outlaw 7700 amp / (4) Def Tech UIW-RSSII (LS/RS/LB/RB), Samsung 46” 3D LCD