I would not recommend anyone learn Bagua from a video.
I got the 8 door conditioning when I was in Beijing since the guy I was learning Xingyiquan with at the time also taught Bagua and was trying to convince me to come to his Bagua class, it was I believe he taught Cheng style. However my limited Bagua background was in Yin style 8 palm and the other form my teacher taught me he called Dong Hai Chuan style...which of course does not exist, but after a bit of research I discovered it looked a lot like Liang style so I bought the DVD. I bought the Fundamentals recently as a refresher to what I had learned when I found myself once again walking the circle. However that stopped in favor of....now I know this will come as a shock..... Xingyiquan stepping and all its variations :EG:.
But back to the Zhang Quan Liang DVDs, I rather like them