Recommended amp for Thiel 3.6 -- newbie

Hello all. As a newbie to this, I’ve read a number of the forum posts, and have gotten some wonderful information and education. And, as this particulary question, Thiel 3.6 recommended amps, was pretty old, thought I’d post my own specific questions. I know so little about this, I’m sure to make some idiotic mistakes, but I’ll learn.

I just purchased a set of the Thiel 3.6s, and then read that they’re significantly hungry for both power and quality components. Although my budget is not unlimited, I have no buyer’s regret, as these seem to be a wonderful speaker set to grow into, with advancing upgrades as time goes on.

My room is about 27’x40’x9’, rug floor, combined living room, dining room; with the entertainment center in the right half of that space. My listening area is about 14’ back, and I generally expect to listen at mostly low to moderate levels. I like accurate, but I don’t like loud. I confess the system I was looking at was Denon AVR-x7200, rated at 150wpc -- but even that is confusing to me: One place says 150wpc, another 260w. The specs seem to be high at 0.05% THD, but the boards seem to reflect that many aren’t a fan of the Japanese disclosures. On all the boards I’ve read, no one recommended that system, in favor of, say, Theta, McCormack, Adcom and others. And the crickets were pretty deafening.

My prime use is for music from those speakers; but I would love to plug in HT application as well, with ultimate 4k passthrough, Network Attached Storage, Internet Radio, and Airplay and/or AppleTV -- those are the things that led me to the Denon in the first place. And even though the boards were critically silent (only one reference, and a negative one at that), I wondered if it was simply because those threads were old.

So for now, I’m kind of looking at Theta -- almost certainly in the used market. I saw a Dreadnaught unit go off recently, so perhaps with enough patience a similar thing might come around again. And see also (currently) a Casablanca unit. --But this is confusing. The Casablanca seems to return some of the HT features that I’d like, and while I’d like to think this is a solution, read the term "pre-amp", which suggests to me that this alone would never be a solution to power those Thiels. Perhaps this AND Dreadnaught. Or something similar. Or something else. --And for that matter, might the Denon 7200 itself, if not an ideal system, be used as a "starter system" -- acceptable for now -- and then morphed in pre-amp type of deal later, using it's connective controls, with some sort of quality amp downstream?

Thanks much for the consideration to this question and long post.