Instead of selling the cats (and Luka, unless you can sell him to a reputable breeder), why not adopt them out to a family who will take care of them? Just make sure that the people fill out an application, do a vet check, a home visit.

Hope that all goes well for you and your pets. I don't think anyone would be angry at you, you have to do what is best for you and for the welfare of your pets. No one would envy your position, I am sure.