Sale on the Die Hard bluray collection today on Amazon for $25, plus a ticket to see the new one. http://www.amazon.com/Die-Hard-Anniversary-Collection-Vengeance/dp/B00ANGID14/ref=lh_ni_t?ie=UTF8&psc=1
Now all you need to do is pick up some RF-82IIs and an RC-62II and put your RF52s in the rear and make your RB51s as heights or wides and you'll be set =^P
To me, I already have too much wireless stuff in my house, no sense on adding to it if I don't have to. I don't like the idea of wireless speakers in general tho, it just seems like something about them wouldn't be as good...
Since the RS-7s fire off to the side, you wouldn't really need to point them at the listening position, but as said above moving your couch forward would also help out.
as said above, you will most likely prefer the RSs on the side. It's always worth a shot listening both ways to see what you prefer yourself tho. You can read about mine in my review link in my sig.
Whatever you go with, hold on to those 52s and use them as sides or rears. The 7s would be sweet, so if it fits the budget, I'd go for it and save up for the 64 because yes, it is timbre matched with the 7s.
You shouldn't have to pay more than $650-$700 for the SW-115. I really like mine, but my space isn't as big as yours. I would think that that it would do you nicely.