An Experiment In Copyright

Nobody wants a guidebook to the Gaza strip right now, however fascinating the place is. And here I have been spending a lot of time writing a book about something somewhat similar, and been struck by a similar situation.
Actually, two books. As I mentioned in a previous post, I want to do an experiment which tests how much more business marketing brings. One book is the one I wanted to market, the other one I will publish on Amazon without any marketing whatsoever. But not this book, not right now. Nobody would buy it while the situation is this unclear.
So I have two choices: Complete everything, and wait until the situation clears up. Or realize that I have spent half a year writing in vain, and produce two different books. That is most likely what I will do, I have more than enough raw material. I have been rewriting it compared to my original book, covering a different topic altogether. But using the same material, creating two different books. Well, one so far.
That is part of the problem: The books can not be too similar. Amazon does not approve a book for sale if it contains the same text as another book. Which is quite correct, as it would most likely be stolen from the rightful author. However, if you are the rightful author, then you should be able to it. But you are not. In particular if you use a pen name. Which I will do, for a very different reason (it makes it a lot easier for the reading audience to find your other books if you use different pen names for different genres).
So the two books have to be different. How different? Well, when I write "explosive growth" in one, I have to write "growing by leaps and bounds" in the other. They may have to be slightly differently organized - one will have to start with the things that the other ends with. Ideally, the style should be different, too. That is much harder to achieve, since we always tend to favor our voice over anything else. But I will certainly try.
In case you did not know, this comparison is fairly easy to do. There are tools like Copyscape which lets you compare if two different texts are similar. It can also look at search results and tell if the text is similar to any search results. The reason is that such a tool exists is that there are certain situations where you have to use your original words. Marketing is one of those, and as a filler around advertising. If everyone were to cut and paste the exact same things the search results from Google would all be the same and there would not be any competition for the best spots to place advertising, which means Google would not make any money. Unless the copyers & pasters all copied & pasted from material out of copyright, there would be some who used words that others had come up with. If they did not have permission to do so, and made a lot of money from it, they could be sued for damages resulting from the copyright infringement - essentially, taking business from the original author.
That is the major reason Amazon does nor want to allow duplicated works, because if they did, and someone sued, they might become liable in some way.
I am actually about 60 % done with the first rewritten book, and I am ready to fill in more material. I need about 10000 words more to make it long enough to motivate a decent price.
If you have any experiences from traveling with children (up to age 6 or so) that you do not think other people may know about, drop me a line and let me know. That is the kind of stuff I am looking at for the present reincarnation of the project.