DeckLink Duo 2 Card (There are newer versions available)

https://www.amazon.com/dp/B01EKGTZ8C/

Sonnet Echo Express SEIIIe Thunderbolt 3 Enclosure

https://www.amazon.com/gp/product/B07XHP2D12

Also got a few SDI/HDMI converters
https://www.amazon.com/dp/B08P3TCMT2/

And some thunderbolt cables

https://www.amazon.com/Anker-Thunderbolt-Supports-Charging-Transfer/dp/B08D9J8HM3/

What are you doing with HDCP that would be a concern? I think just about everything is gonna give HDCP issues unless you strip it.

You could look at something like this: https://www.amazon.com/Blackmagic-Design-DeckLink-Playback-BMD-BDLKDUO2/dp/B01EKGTZ8C

There is (or was?) audio over SDI issues with that (or we did, confirmed by RV), so you may have issues with embedded audio.

If you then need additional outputs, just add the distro. You'll of course need SDI to HDMI converters, though.