Opinions on equipment upgrades

[Vtach]

I would stick with the standard hose setup.  Miflex are nice for special applications but I have heard that many users who converted their hoses over were not happy with the conversion.  The hoses are more flexible than standard hoses and they don't always stay put when you want them to.  In addition, they are more expensive than ordinary hoses.

Regulators are life support equipment, ditto what everyone else has said.

Education is an investment, almost like top of the line equipment for your brain.  The best paid money is usually spent on training.  If you are interested in the technical side, the intro to tech class is a great investment.

There are many manufacturers of drysuits, DUI is a good one, Bare is a good one.  I have also heard good things about Pinnacle and Diving Concepts.  Like already said, the best thing you can do is make sure you get a suit that fits you properly.  Don't be afraid to spend extra money on a custom suit if none of the stock sizes fit properly.  You will be probably be happier in the long run.