I went through this exact dilemma when rigging my R7 last year. Honestly, the reviews about the SmallRig Black Mamba Cage for Canon EOS R7 4003 are pretty accurate. If you have larger hands, you might want to consider how tight that top right clearance is. It looks sleek, but accessing the top dial near the shutter button is kinda painful during fast shoots. For a run-and-gun doc setup, I would suggest going with the standard SmallRig Camera Cage for Canon EOS R7 4002 instead. It is bulkier, but it gives you way more mounting points for accessories like a monitor or receiver. Just make sure to check your top handle clearance if you use the hot shoe for audio. Also, be careful with the battery door clearance on the Mamba since some quick release plates block it.

> The standard SmallRig cage seems bulkier but maybe more practical? Unfortunately, that standard one is overpriced imo. Had issues with ports. Check the YouTube reviews on Neewer Canon EOS R7 Cage vs 8Sinn Canon EOS R7 Cage, they are cheaper and offer way better clearance.

Oh I love the R7 for video! It is such an amazing camera! Before you buy anything though, what kind of accessories are you planning to mount on this rig? Are you planning to run a heavy top handle or a massive monitor? I ask because my biggest worry with cages is always stability and safety. Some of these tight-fitting cages only secure at the bottom, and if you mount heavy stuff, the camera can literally twist inside the cage! That is super sketchy and can totally ruin your mounting threads or worse, drop your gear. You definitely want something that has multiple points of contact, like locking pins or a side attachment. Also, some cages block the battery door completely if you use certain quick release plates, which is a total nightmare on a shoot! Let me know what you're mounting and I can share what worked for me!