I get what you are trying to do, personally i think its an overkill, but there are workaround to the inconviniences that NoFan95C brings.
i would prefer to use pci slots for ssd memory, maybe wireless ac, maybe high end sound card, maybe more usb ports
Lets address each of your desired extras,
1) Wireless AC
There are motherboards that come embeded with it, its not that hard to get. Here are four options, including the mighty
taichi that has been reviewed as one of the best ryzen boards by techpowerup.
ASRock X370 Taichi
ASRock X370 Killer SLI/ac
ASRock Fatal1ty X370
ASUS CROSSHAIR VI HERO (WI-FI AC)
2) USB Ports
You can use the 2 PCIe slots that are blocked by the NoFan95C with
2 Port USB 2.0 Rear Bracket Extension for PC Motherboard - 12" you can even get extensions to route the cables easier like
Duttek 1M/3.3Ft 10 Pin Motherboard PCB Cable Male to Female Header Extender Extension Dupont Jumper Wires Cable (10Pin M/F), it can be done with USB3 also but a little more complicated.
3) Dedicated Sound Card
You should have at least 5 PCIe slots free for you to install it.
4) PCIe SSDs
Same as the above you still have 4 PCIe slots free. Intel PCIe SSDs are imo the best in the market, just expensive, but if i ever go pure PCI this is what i would buy,
Intel 750 Series AIC 400GB PCI-Express 3.0 x4 MLC Internal Solid State Drive (SSD) SSDPEDMW400G4X1. Some motherboards allow to use the U.2 standard, that its to connect a PCIe SSD through the U.2 connector, also intel has a very nice product, that could be a good option for a very low airflow setup like you are planning as it has its own heatsink,
Intel 750 Series 2.5" 400GB PCI-Express 3.0 x4 MLC Internal Solid State Drive (SSD) SSDPE2MW400G4X1, remember to use this you need U.2 port, here are two that come with it,
MSI X370 XPOWER GAMING TITANIUM and
GIGABYTE AORUS GA-AX370-Gaming 5