Hey now, I wouldn't call the selection of brands available "mediocre". There are some truly top-level performers in there. Not necessarily the highest
value or "bang-for-the-buck", but certainly not a limitation to only "mediocre" brands.
A NuVision TV? Really? I'm sorry, but I have to shake my head at that one. Your father got taken for a ride with that purchase. A Panasonic TC-P65VT30 with a professional ISF or THX calibration is every bit as good, possibly even better than the NuVision for nearly 1/4 the price. So I'm getting the sense that value really isn't what motivates your father. I'd have to assume now that he goes by "gut" feeling, because there is no measureable or rational reason to choose the NuVision over the Panasonic unless he thinks the small difference in the look of the frame is worth almost $8000 difference!
With the budget growing so quickly and easily and such a unnecessary expenditure on the television, I don't really see any reason to offer any more serious recommendations. Just have your father go to the dealer and let him audition gear and buy what he likes. Like I said earlier, I wouldn't really say there are any truly "bad" choices with the brands that dealer is offering. And they'll be more than happy to let him audition if he's going to be dropping that much cash with them!
He'll probably end up with Macintosh separates at the rate he's going! Even though the Denon 4311 with a good, solid amp would actually be a better choice. If he was somehow swayed into thinking the NuVision was a good idea over the Panasonic VT30, then I can't imagine talking about measureable performance and value for his money is going to mean anything.
He liked a whole smattering of very different sounding speakers, so there is absolutely nothing obvious in terms of characteristic traits that I could point to as a common link between the speakers that he enjoyed. About the only thing is that you did NOT mention the Def Tech or Mirage speakers, so something a little closer to neutral and direct seems to be about the only common trait. Out of the brands you mentioned, the Energy Veritas are about the most neutral and quite easy to drive with any amp, making them a good "middle of the road" choice, IMO. The Klipsch will most easily handle the room size, the Martin Logans would likely struggle the most just in terms of sheer output and dynamics. And the B&W speakers very much have their own character, which many, many people enjoy, but they aren't exactly neutral and they're not overly efficient or inefficient, so a good, beefy amp would drive them fine in the room size.
For subwoofers, my bet is that your father will wind up getting subs that match the brand of the speakers that he chooses, even though that is totally unnecessary and often a good way to spend way more than necessary. Never-the-less, Martin Logan and Paradigm both offer some very capable, but very expensive subwoofers. Klipsch is OK too if you go up to their top-priced subs. Energy doesn't really have much in the way of good subwoofer offerings.
I've no idea why the dealer would convince your father to go 5.2 over 7.2 unless they talked at length about setup and available positions for the speakers and worked out that there simply won't be any good positions for the rear speakers. If your father stressed music over movies, I could see them recommending 5.2 over 7.2 since there are only 5.1 multi-channel music formats, no 7.1 channel music formats. He'll probably wind up with the "rear corner" placement of the surround speakers, which is in line with a multi-channel music setup, but not the traditional movie speaker placement. There's nothing wrong with that, especially if music is more of a priority.
If there is anything that you should absolutely put your foot down on, it's going to be the cables. If he bought a NuVision, there's no sense in trying to sway his speaker, amp and turntable decisions. Let him audition and decide for himself. He'll be happier and the dealer will certainly be happy! But if they try to sell him expensive cables, that's the one place where you should absolutely put your foot down. It might not matter. It's his money and he can waste it if he wants to...clearly. But expensive cables are a PURE waste of money and can ONLY be sold via misinformation and outright bilking.
Honestly, after the NuVision purchase, I don't think I have anything else to offer in the way of advice at this point. It's not that it's a bad TV. It's just that it's the same thing as buying the $3500 Lexicon Blu-ray player when it is LITERALLY the $500 Oppo Blu-ray player with nothing more than a Lexicon case on the outside. There's no sense in it. Not when there's the Panasonic VT30 right there offering the same level of performance for 1/4 the price. Anyone who is that easily swayed by looks, dealer's words or just the allure of a brand name should just audition and buy for themselves. I'd prefer that he buy the Panasonic and donate the difference in price to me, but that doesn't seem to be the way rich people work, so I'll leave it at that
