Recording all four inputs of Decklink Quad?

Is there an affordable software package for recording all four inputs of a Decklink Quad card? I know I could maybe script something up with ffmpeg, but wondering if there's something that will record all four inputs like in a DAW. I don't really care about the OS...Linux or Windows is fine with me. I'm just looking for a multi-channel recorder that will have all sources sync'd up.

Thanks!

Maybe I should redirect the question...

I was originally considering getting a Decklink Quad to capture four sources at once like in a DAW. The idea being that the four sources would already be "sync'd" up and ready to edit. All I would need to do after recording is add the sources to a project and start chopping.

So I'll step back and try this again with a specific scenario:

I'm interested in doing a long-format 2-3 camera shoot with PC screen grab and perhaps some external audio all synchronized and ISO for later editing together into a final production.

The computer screen to capture is 4K, my Panasonic G7 can output up to 4k over its HDMI port (but it can't record natively more than 30 minutes), and I was pondering maybe another G7 or some other camera or two as additional angles. 4K isn't necessarily a requirement, but I'd perhaps have to scale the computer capture down to fit in HD.

Sooo...How would you guys do this? Some sort of dedicated recorder like a BMD Live Assist or Atomos? Can I do this in software with a Decklink card?

Thanks!