I wouldn't recommend buying textbooks until a few weeks in when you will at least know if you really need them or not - trust me, there are a few books that I bought last year that I would rather have just read in the library and kept my hundreds of dollars.
As far as specified text goes, the specified text is the one that they should be writing the bulk of the lectures for, thus the most important one. If you read it you should cover almost all the same material. Recommend extra reading is usually a double up, or for a topic we only cover briefly.
Lab coats are not really a must have item till second week either, they are a good buy though, I have a feeling we'll be using them alot. (I'm just going to be a rebel though and use one with QUT stamped across it)