1. Do you plan to have a printed version along with an epub version?
2. Is the content for the guide prepared in Word or other text editor?
3. Employee benefit guides can have many tables to represent information, will your guide have tables?
These are just a few questions that need answered before making a decision, and here are some example answers with the explanation:
1. If Yes, then Indesign would be best to manage both outputs
2. If Yes, exporting a properly formatted/tagged Word doc from MS Word may work
3. If Yes, tables can be problematic, and editing in an app like Calibre might be required
1. Yes, we will have a printed and ebook version
2. We currently use publisher and only offer a printed version. We want to convert this to InDesign, the text would be loaded from Word or typed directly into InDesign
3. Yes, we will have many tables
Do you prefer CC or CS6?
I think tables will be more of an issue/concern than what version of Indesign you use.
Here is a link to EPUB Assessibility with tables, notice the first sentence "When tables are not structured accessibly, the data they contain can quickly become a meaningless sea of numbers..."
I am not suggesting this cannot be accomplished, however it may require a lot structing, formatting, modifying and testing.