I'm with lute. Whilst it's really sweet that you're helping this little bird to recover from injury, I do not think it's wise to keep him. He was born a wild bird so no-one has the right to take that away from him. Of course, you know that his injury may stop him from walking properly, but don't consider captivity yet. I would suggest taking him to the vet if you really think the injury is that bad, and your vet will have information on what should be done. He may be able to go to a sanctuary for wild animals that for some reason can't be released. He would be much happier in an environment like that than taken into very unnatural surroundings.

On the site you posted, they are birds bred for captivity. This is a wild bird, he deserves the best life possible. If he can't be set free then try and find the best possible place for him to live.