This is an excellent totorial. I would mention one thing. In order for everything to work you must have the block "suqared", or all side must be at an exact 90 degrees. This is where a high quality band saw comes in. Most cheap band sawa will not give you the precision you need and when they don't your bowl hole and draft hold will not meet properly.
There are other threads on this subject if you search them out. As to a good band saw for pipe making (as I said before) an Inca is an excellent choice if you can stand the price.