I'm not familiar with the companies you mentioned, and I have no fame at all. If you want to take the IE exam, go to ITAA Tom. If you don't plan to take IE, I suggest that you don't need to find a big training institution, because the tuition is too high and the things you learn won't be too bad. If you want to do network engineering in the future, NA is not enough. I suggest you learn NP. It depends on what certificate you want to take. You need to pass NA to get NP. But I don't need anything to take the IE exam.