Pacrat

I've decided to go with a Vive VR unit, but I'm not sure which one to go with. There are no stores local to me that seem to know much about the different models and I haven't had any luck finding current comparisons for the new units. I'm not sure if I'm not putting in the correct tags for the search or now. Can anyone direct me to the proper place to find a side-by-side comparisons of the different units?