Looking for Advice on Focal Speakers

I would not buy the Kanta without listening to them first. I love my Focal 1007 Be standmount speakers, so much so that I bought them back from the friend I sold them to.  I have listened to the Kanta 2 with ARC (Audio Research) gear, and was underwhelmed. Maybe it was the ARC gear that was too solid state or cold sounding to me, but I remember wondering where the bass was at. Quite anemic in this regard. You would likely want to buy 2 subs.  Sopras are amazing, would likely be an end game speaker for me. I think used Focal 1028 Be would be a great buy, and something that would show improvement with nicer electronics down the road if you choose to upgrade. My 2 cents 

It would be interesting to compare Kanta 2 with 2 REL T7x subs versus Sopra 2s — I suspect it would be pretty damn close to what you get for the 20K Sopras. 

If it were me, I would buy a solid state integrated amp or a tube preamp to pair with the Parasound amp. I would keep the Marantz receiver for home theater.  Might not be true for all of the Focal speakers, but in general you will need more tube watts than is offered in most tube integrated amps to drive Focals properly, due to their impedance curve.  At a minimum, I think you would want the 120 watts of a Rogue Cronus Magnum — but I know Kevin Deal at Upscale Audio sells a LOT of Prima Luna integrated amps paired with Focal speakers, and would strongly argue otherwise. As mentioned above, Prima Luna have HT bypass.  

Depends on what you are looking for and your budget.  If you want HT bypass, get a preamp. If a 3D soundstage is really critical for your listening enjoyment, get a tube preamp. A Prima Luna Evo 200 preamp will give you both but set you back $3400. A Schitt Freya+ tube preamp is very high value at around $900 I think, but doesn’t have HT bypass. Plus you will need to invest in interconnect cable.  If space and/or budget is at a premium or if your wife is pushing for less boxes, get an integrated. I personally like the flexibility of separates in terms of experimentation and tailoring the sound to my liking.  You already have the amp. I have not heard the A23, but know the A21 was designed by John Curl and gets very high marks. Supposedly has a warmer, less resolute but more engaging sound. Should pair nicely with the Focal Aria I think. 

As stated before, I would suggest 2 different systems— Marantz for HT/TV, and then a 2 channel system. Your wife can watch Bob’s Burgers til the cows come home. 

One last bit of advice. If you cannot home audition equipment from your local brick and mortar audio shop, or travel to listen to your narrowed field of choices, there are many companies that will let you home audition for 2-4 weeks provided you pay a nominal restocking fee if you opt to return it. Schitt is one such company, and the $900 Schitt Freya+ tube preamp has been said to offer 85-90% of the performance of high end tube preamps. FWIW. 

I gave advice based largely on your original post, as a fan of Focal speakers. There are many separate threads on this forum dealing with your subsequent questions with advice from others wiser than I. Most on this site would tell you to keep the integrated and DAC separate, mostly for the reason that DACs are likely to get better over time — but also because you are out of commission if one of the parts go bad (most likely the DAC). I think most would agree that a solid state integrated likely has a shorter lifespan than a corollary separates system, given the impact of heat on the circuitry. Cool running Class D integrateds however would be an exception I think. I would not pair Class D with Focal speakers IMHO. I think most would tell you that the sound of separates (amp + preamp) exceeds that of an integrated, but the margin here has gotten smaller over time, and really high end integrated amps are perhaps equal to or better than separates (the argument being there are shorter signal paths with no need for interconnects that can color the sound). Robert Harley gave a highly favorable review >5 years ago on the Moon 600i integrated, stating it gave separates a serious run for the money. This is likely outside of your budget. As an aside, I am also a fan of Moon and believe that integrated with Sopra 2s would be a giant killer, and compete with systems twice its price. There are threads on the issue of HT bypass. I am in the camp of keeping 2 channel and HT systems separate. Hope this helps — but again, I am one person giving you his opinion so keep that in mind. Best advice perhaps is to use this forum to do your research, narrow down your choices, and then let your ears decide.