do you have a hundred or so dollars?
Go to a granite or quartz counter specialty store. ask them for a scrap cut out from a countertop (usually have the sink cutouts laying around if the customer hasnt taken it as a glorified cutting board). If they cant do it - they should know someone who can. Most machine shops with a CNC machine will be able to do it. just need the right bit.
ask them if they can do what was suggested above - route a channel and drill a small drain hole.
also have the hone and polish the edges for a nice finish
