Ugh... lots of information and such to digest...

Take this FWIW, I see most of this stuff all day everyday, while moreso commercially than residential. The concepts, applications, and products are similar enough.

For the receiver, while Integra, Yamaha, and Denon (list in order) are good products, The Arcam is SO much better standing heads and shoulders over the Denon, a head above the Yamaha, and a bit over the Intergra, why look further? I really think you need to go audition it and give it a run. Also I will search and see where has both products (Arcam/Integra) so you can listen back to back. not knocking Yamaha, they make a quality product, but I have seen far less issues with either Arcam or Integra. And with the Arcam, hard to argue British quality when refereced to audio.

Speakers... Those are a decent selection of entry level speakers, but going with the Paradigm, I would think you are in a level higher than what you have been looking for.
Have you ever considered B&W? They are incredible, and I was very pleased with how they turned out, and we outfitted a high profile client's home in Aspen with them. HIGH bang for the buck here.

How about:
JosephAudio? They are decent and sound good, worth a listen.
NHT? Great sound for a lower price point.

Taking me to B&O, while not a bad product in quality, function, design it really isnt for me. Biggest reason is you can get SOOO much more for less, why bother with them.

Next up is Bose, the old monniker is VERY true "No highs, no lows, it's gotta be BOSE!"
These guys are living off a reputation buoilt in the 70s and 80s when they HAD a decent product. Not the case anymore, and much like Sony, living off a reputation from the past but have really cut corners in the mass production realm. Like B&O, WAY overpriced for what you get, not to mention the speakers are NOT effecient at ALL!
Takes way to much power to even come close to driving them anywhere near a level where they might sound good, on a day that the planets align, with the wind coming from the south east @ 10MPH, with a relative humidity of 69%, with a 20% chance of precipitation...
but I digress. These "big name vendors" that are in every mall, etc in the country have to, like the previous poster implied, pay their rent somehow and who do you think pays for it? thats right, you do.

Which brings me to Monster cable and the other interconnects that you pay 1000 times more than you need to. Ill tell ya, the raw cable, and connectors I use on a daily basis not only looks no different, it tests out no different than the monster, et all stuff. So, why pay $50 for a cable when it could be done for $5?

The in-wall stuff, while it is good for stealth looks, and you can do so in a way that it is imperceptable to the human eye. Very trick, but very expensive. There are products that exist for in wall that are aimable, and directional. For my money, I would just get some decent cup and ball mounts from either the ceiling hanging down and in, or the wall. Either way, with the ball mount, VERY easy to aim the speaker for optimal imaging.

With the plasma, it doesnt buzz right away, it develops after a few hours of use. Typically within a month of install I have been called back. Havent dealt with the Dell much, so I cant say, I suspect that they are rebadging a Samsung anyway. Which BTW, has been better than that LG/Zenith brand. Have had HUGE issues with them. What size did you end up with?

I really can go on and on, but I think I have spewed enough info for now. As with all things YMMV. I can only share what experiences and opinions gathered from those experiences.
Let me know if you need assistance or additional info.