I am not aware of any kits available to add slideouts to an RV. But there are outside companies that do this.
It is not as simple as just adding a slide out, your RV has to be re-engineered to so that it can handle the additional strain caused by a slide out. You should read the answer I gave to the question below and you may end up changing your mind about adding a slide out to your RV.
Everything-About-RVing.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon.com.