Disc pad identification chart

I am planning to fit an non-standard four pot Calilper to the front disc, but I don’t know where I can obtain replacement pads from. I don’t want to fit the calliper and then discover I can’t get any pads to fit it.
Does anyone know of a chart that shows the size and shape of brake pads, so I can be certain that I can obtain pads in the future?
Does anyone know of a chart that shows the size and shape of brake pads, so I can be certain that I can obtain pads in the future?