Grumpy cat is not a breed. Grumpy and her brother Pokey have some deformities that make them look like that. Here is video that shows Grumpy, Pokey, and their mom Callie. Callie is a normal calico kitty. ~ https://www.youtube.com/watch?v=kWpmcIPDU3Y
Some of the places where you can sell you grumpy cats include zazzle.com, olx.com, petside.com and ebay.com. You will be required to post the particulars of the grumpy cats in these stores for you to get a good buyer.