Paradigm or Energy?????

If you must keep that receiver(believe me, it's not going to be anything special sounding on it's own), you would have INFINITELY better sound if you just bought something like a nice used pair of Energy C2 monitors(class C stereophile) for $200 used, bought a better dedicated amp to drive from your receiver(escentially doing a pre/pro and amp combo), RAN THE SPEAKERS AS SMALL from your receiver/pre-pro, and used a powered sub to do the bass!!!! You would spend about the same $850 for the amp and speakers,but you'd have way better sound!
The receiver thing just isn't going to do ANY speaker justice on it's own for you...really! Also, you're going to HAVE TO HAVE A SUB anyway, so might as well take advantage of it! That's my thinking anyway.
I know VERY VERY WELL from first hand experience, all the speakers you are considering above, and I understand the roll your receiver would play with them. Really, things should be much better for you!
I used to run a pair of modest($600 new) Energy C2's ($200 used) as a budget system monitor, and ran em with a pre/pro and Acurus 125X5 amp($600 used). I crossed the speakers over as "small", placed em well for great sound, and dialed in a quick 8" 100 watt sub in a smaller room. The sound was SO GOOD you'd be amazed for the $$$!!! For rock, HT, heavy dynamic, all the way to classical and vocals, the sound was just WAY GOOD OVERALL! Yes, I've put together better systems, but for lot's more money. And, in certain area's, the c2 sytem was as good as my ref rigs over the years!
I just know the sound you're going to get if you go with something like some Paradigm speakers, or whatever, and drive em with a rather unimpressive receiver!..it's not going to be anything to write home about really. I think you'll immediately long for better, and ultimately be dissatisfied.
These are just inputs of course, and it's all fun and good!
have fun...

Of all the floor standing speakers you just mentioned, I think the Energy C7's have the most potential NEW. They DEFINITELY need WARM GEAR TO MATCH WITH THEM! Infact TUBE GEAR(not likely) would be ideal. The Paradigms are kind of AVERAGE, WARM, AND "just OK sounding" in the monitor 7's, and the AE's about the same.
Are you talking ONLY about $850 NEW? or is used factored into the equasion? Also, how are you planning on running the speaker for HT or Music? I assume you're looking for full range for music, yes? However, you WILL NOT be playing these speakers FULL RANGE FOR MOVIES, ESPECIALLY IF YOU ARE USING A RECEIVER FOR POWER! They can't handle it! They'll sound weak, distorted, strained, mushy, and blown out if you do! For music, you might get away with running full range from your receiver(?). But you'll still do better with these kinds of speakers with heavy percusion, rock, and heavy dynamic stuff if you run em as "small", and let the POWERED SUB handle the bottom register in the bass.
If you are going FULL RANGE speakers at that price range, may I suggest THE USED MARKET!?! You will get much more value for your money, get better speakers potentially(making wise decisions of course), and be in another QUALITY league! At that price range of $850 used, you can get better speakers in FULL RANGE models, starting at the bottom(although still excellent for the $), with something like used Energy C6's(c2's are a steal), NHT Super Two's, PSB stratus Bronze or Silver(much better!) at $850 used or so, POWERED Definitive BP2006's-BP2002's used(use warmer sounding receiver or gear), Paradigm Studio 100's used(pretty nice, if a little warm sounding) at $850 range, etc.
have fun...