I agree maybe have it vacuformed in plastic and then paint as metalAgree with Bill.... this would be very expensive! Could you cnc route aluminum to make it look embossed? I would come up with a way to make a faux like embossed version. Or guide your client in a different direction.
If somebody asked for that at my shop, id suggest an ACM panel, and acrylic lettering (i assume it's lettering?) pushed through as per the attached.
Price wouldn't be too crazy.