5D mark IV or III External Monitor recommendation

Hi there DSLR community. Mr independent film maker/cinematographer here.

I'm currently looking for an external monitor to output a live feed for the director to see how the framing looks. The camera(s) we'll be using is in the title above. I had a little skim through rental places that have these monitors like the Atomos Samurai Blade 5". (And that's all I found that was compatible with 5D). I'll also need it to be portable... so yeah... Any recommendations?

Oh almost forgot. Here's my budget. Below or just $1000NZD.

This is my first time posting in Reddit so go easy on me sunshine.