As far as I'm aware DNxHR is for greater than HD resolutions, you seem to be working in an HD format so DNxHD might be adequate?
I've literally just switched from encoding my H.264 footage to DNxHD from ProRes as I've found it to be more windows friendly, Resolve is certainly more snappy for me using DNxHD 145 as my footage is only in 29.97 fps.
I think I tested DNxHR and the files were way bigger for DNxHR HQ with to my eyes no visible improvement, the original footage is from a GoPro 3 so its not like its amazing quality in the first place.
This is just MY experience, waiting for someone who has more knowledge to come in and maybe suggest I could have used DNxHD 100 or even 45 and still got the same quality based on my original footage.
This wiki link gives a list of the types DNxHD available for a given resolution & fps : https://en.wikipedia.org/wiki/List_of_A ... esolutions