Oh, just re-read and figured out that you don't have a processor/amp setup yet. You only have a AV Receiver (which is okay, but leaves a huge area for upgrade). So, my comments:
You can't really use a "preamp HTBP" with your current receiver unless you get a separate amp for this scenario. If you want to upgrade your entire HT, I would go with the Krell Foundation 4K at a minimum. When you are ready to support 4K HDR video sources, you can always get the Krell 4K HDR switcher to handle this (it works with the Foundation 4K).
If you just want to do the HTBP route, you'll need to get a either a preamp/amp setup or a really good "integrated amp" such as the Kinki Studio EX-M1+ and use the pre-outs on your receiver to drive any HT movies. Then you can go your direction with Denafrips / Prisma NP5.
I wouldn't really consider the Marantz 7706 just for "8K" support. In my opinion, we really didn't need 4K unless you had a seriously large screen (such as 70" diagonal or higher). What really improved things was "4K HDR" which expanded the color and brightness range. At this point, 8K becomes almost nonsensical (but it's the next big thing so consumers will glom onto that).
If you do the Prism NP5, I would seriously consider a linear power supply upgrade (I'd recommend Farad Super 3 or even a lower cost Teddy Pardo). This will significantly improve your sound quality for that Denafrips.
You can't really use a "preamp HTBP" with your current receiver unless you get a separate amp for this scenario. If you want to upgrade your entire HT, I would go with the Krell Foundation 4K at a minimum. When you are ready to support 4K HDR video sources, you can always get the Krell 4K HDR switcher to handle this (it works with the Foundation 4K).
If you just want to do the HTBP route, you'll need to get a either a preamp/amp setup or a really good "integrated amp" such as the Kinki Studio EX-M1+ and use the pre-outs on your receiver to drive any HT movies. Then you can go your direction with Denafrips / Prisma NP5.
I wouldn't really consider the Marantz 7706 just for "8K" support. In my opinion, we really didn't need 4K unless you had a seriously large screen (such as 70" diagonal or higher). What really improved things was "4K HDR" which expanded the color and brightness range. At this point, 8K becomes almost nonsensical (but it's the next big thing so consumers will glom onto that).
If you do the Prism NP5, I would seriously consider a linear power supply upgrade (I'd recommend Farad Super 3 or even a lower cost Teddy Pardo). This will significantly improve your sound quality for that Denafrips.