You can resell ebooks, as long as you buy a license to do so. Just pay attention to where you're getting them and that they're not all over the web already. I find resell products to be good as bonuses to my own products, but I also sell them separately sometimes.
The best way to do this, in my opinion, is to resell ebooks that aren't in the IM niche. In other words, find topics that can work in other niches and market to those niches. For example, a good ebook on time management will be useful to many other niches and that way it's not saturated.
Hiring a ghostwriter to create a product for you is a good choice, too, providing you hire the right writer. The forums are full of writers that create articles but those same writers often do not have the skills to create an ebook. As a writer myself, that may sound self-serving, but I have hired hundreds of writers through the years and I am telling you the stone-cold truth.