Is there a difference between Dragon Ball Z, Dragon Ball Kai and Dragon Ball Z Kai? After doing a little research, I saw that Dragon Ball Z Kai and Dragon Ball Kai are the same and that they are just remakes of Dragon Ball Z. Is this correct?

I know that Dragon Ball Z has around 300 episodes and that Dragon Ball Z Kai and Dragon Ball Kai stop after the stage with cell around 100 episodes. So which one is better for watching with an English dub?
Since there can't​ be one particular answer to this question and others can only give you their opinions, I will say Dragon Ball Z original is much better than Kai and I liked the old voices more than the new ones in the dub version.

The other thing is Dragon Ball Z Kai does not have any fillers. I have watched both, and I even thought that losing all the fillers would be a great thing, but I mostly found it frustrating. Some of Gohan's more awesome rage moments were shortened and worse yet the battles just were not as exciting.