IN my research of epoxy, there are several large, successful players who seem to understand what needs to be done in prep work and have a quality product that a good DIYer can apply. Then there are paint manufacturers who jump in with something similar to "epoxy", yet they know nothing about concrete or surfaces or the prep needed. Then there is paint....just slap it on and go to work.
The reality is that ANY epoxy work, be it garage floor or boats (most of my experience) is in the prep work and using quality products, correctly mixing, and then applying the epoxy correctly.
Poor prep will render the best coatings useless, or worse, a failed setup and require additional work to remove correctly. Then start over with your install. Good epoxy is not inexpensive.
Look at what your budget is, the quality of the floor as you look at it today and what will be needed to prepare it, correctly. Then do your research or talk with one of the suppliers who are here day in and day out. Stay away from the box store paint and "epoxy kits"....
Best of luck in what you decide.