I would start with a screenbar and see if it fits, as you are talking about 27 inch monitors.
Depending on the desired illumination, it may well be that it is "rather too little" for two monitors with a screen bar (as the previous speaker said).
I have a curved monitor and it's ideal for me. If I had two curved monitors, I would work with two screenbars for my personal requirements.
Try it out and order a second one if necessary.

Not really in terms of illumination. The question is how strongly the monitors are angled and how well the bracket then holds and how much the mirroring/reflection then disturbs the screen.