Lots of books re-publish articles or sections of articles. Journals usually do not. With either though, it is important that it is clear to readers what was previously published.
Well, as you present it, it seems to me that you would be publishing the exact same materal twice so maybe it is not the most ethical thing to do... I certainly would not do that, but I know of many people that have done. So, in the end, it is just up to you since it is your own work and reputation.
There is no such thing as "self-plagiarism". Full stop. If you have assigned copyright to the publisher of article (1), then in article (2), with a different publisher, you can quote a little bit, you can re-present in a totally different way, and you can ask permission. DO NOT COPY LARGE SECTIONS OF TEXT OR CONCLUSIONS. Remember, the reason that publisher (1) may seek to use copyright is because she does not want to lose SALES.