Find a sink that you like and then get someone who works with Corian to cut the hole to fit. We had the Corian peninsula in our TK3 cut off to make it an island, and it came out looking pretty good. You have to know where the cut part was to notice. Corian is a dense plastic product, and it cuts ok if you know how to do it without melting the plastic component.
I doubt that you will be able to find an exact fit for the hole, but maybe there is one out there somewhere. The rest will just be plumbing/carpentry to get it in.
2016 Tiffin 40 QBH
2015 38RSSA, traded
2005 TK3 #1869, 10 yrs of memories,
2017 F450 KR--one more Ford is it
2009 F450 4x4-died; 2010 F450-retired