Best Prep Course?

I won't comment directly on your main question (I have an obvious conflict of interest), but part of the answer to such a question is really very specific to your own needs. Check out whatever free offerings are available from any course in which you're interested and see what would be best for you, given your particular learning style, your goals, etc.

Most big companies offer various kinds of free info sessions or free classes and you should definitely take advantage of those. If possible, try to attend a free session that's being run by whoever would be your instructor so that you can see whether the person's teaching style works for you. And ask questions that are specific to your situation to see whether the instructor takes the time to listen and provide you with thoughtful answers. After yourself and the work you do, the single biggest factor will be your instructor - so make sure you really feel like you can learn from whoever that person is.

p.s. I assume you've checked into our offerings enough to know that we don't hold in-person classes in whatever city you're in, but we do have live on-line classes. The instruction and curriculum are identical to the live in-person classes - the only difference is that everyone attends class via their computers, rather than physically sitting in one classroom.