As for the gaskets, you won't need them as the stock ones are reusable. They feel like they have a metal core surrounded by rubber or a similar material. I can't imagine a better gasket, and I haven't heard of any leaks.
Fluids are another story. You can debate for hours with many on this board, but all I'll tell you is that you need a full synthetic without a friction modifier. There are no clutches in the rear end.