Hi
Just a little something to help.
I don't know of a recorder with HEVC codec... maybe it exists, but I don't know it.
The one I know:
HyperDeck Extreme 8K HDR
The codecs available for recording are:
ProRes, DNxHD, DNxHR, H264, H265.
This unit can record up to 4 video channels. Pay attention to the recommendations. Take a look at the user manual on
page 69.
https://documents.blackmagicdesign.com/ ... 4940811000 
Also, there's the option of using a
HyperDeck Studio HD Plus (
UHD 30 FPS = 6G) a recorder for each camera. If you need
UHD @ 60 fps = 12G, then it would be a
HyperDeck Studio 4K Pro (one recorder for each camera).

With multiple separate recorders, again, pay attention to the connection options to synchronize all recorders with the same timecode, so that clips can be easily synchronized in post-production (editing).
I hope help