Corian is great stuff. Not only can you have decent fiddles, you can have one-piece integrated sinks, draining boards, and even different colours inset. I had Westerly make my boat
with Corian throughout.
If you want it relatively simple though, there are a large number of composite stone copies around most of which are just as good. Much cheaper too. Best plan is to make precise hardboard or plywood
templates and take them into somewhere to have them made up. On a boat you want them as thin as you possibly can, probably backed onto epoxy-soaked marine
ply. Otherwise they weigh a ton.