Aluminum Christmas Trees: Selectively breeding domestic creatures to create something similar to their wild ancestors is a real practice called breeding-back. Its scope, however, is somewhat limited - Tamaskan dogs, for example, bear about as strong a resemblance to wolves as can be gained without actually introducing wolves into the breeding program, yet behaviorally and temperamentally they are still more like dogs than wolves (which is exactly what Tamaskan breeders want anyway, so it works out).
Recreating a wildcat type would likely be incredibly easy, as domestic cats are closer in both behavior and appearance to their ancestors than dogs are, and a cat who has had little to no human contact will tend to act quite wild anyway. There are even arguments that cats are not truly domesticated, and should instead be considered semi-domestic wild animals.
No Export for You: Initially, apart from the first 2 books, the Felidae series had not been translated and released in the U.S. and the English editions of those two were out of print for a long time. Now they are available in e-book form, along with the fifth book, Salve Roma!, which has been translated. So perhaps the other installments will eventually be released in English as well.