Willing to help. I’ve used Nvidia Quadros with multiple monitor setups in the past and predecessor to Mosaic, can’t recall name but same thing.
Graphics card resolution: ‘I need to know what the resolution of the card should be’ - the card doesn’t have a resolution as such, the ports and number of determine what it can support. You have 3 x Displayport each of which can support one of your monitors at full resolution so you’re good to go (given that mosaic is for RTX Quadros they’ll probably do 3 x 8k res if you had it).
You don’t have a problem with what you’re planning to do. If I’ve missed or misunderstood something, elaborate….
Best,