Never publish as is, and never use the same cover and we are talking ebooks and reports here.
It is well worth the time to grab a few reports or books in the required niche and go through them, picking key points from each one and creating your own product by rewriting each passage in your own words. This makes a unique product and you will be amazed how you get inspired while doing this, and then end up adding your own material in as you go. It will be well worth your effort.
Always change the cover, it will have been used many times before and besides you now have a unique product and do not want it associated with the original.
If you use plr as inspiration it can be a powerful tool but make the effort to create something of value, after all your business is worth it isn't it?