I have never seen
Zimri before, but I really really like it! I think I might add it to my own list!
I despise
Hubert, but definitely use it, because it is awesome that it honours your great-grandfather. I have a similar situation in that I will definitely use
Trevor as a mn even though I don't like the name at all because it is the name of my grandfather who is the biggest influence on my life.
I think you should use
Zimri Hubert, it is unusual, not weird and I like it