One thing I always wondered about when it comes to covering fabric for a nurse costume with latex, is that wouldn't the fabric get rather stiff after so many layers being added? The movie nurse dresses I believe were totally latex, and they moved and flexed and were supposed to look fleshy. I'm not about to "crossplay" a nurse any time soon, but if I did I would use a rather light weight fabric for the nurse outfit and then cover that with latex. That way it wouldn't be so stiff, and it would also be form fitting.
Here is a behind the scenes video of the movie nurses that might help you.
Also note that the nurses are not very bloody at all. They are more dirty and worn looking than they are covered in massive amounts of blood.
Another tip, if you buy a one of those cool movie nurse mask that a lot of people have, try to paint the mask itself to match the color of your "nurse" skin as well, or try to match your skin/body paint color to the mask. Either way works. I see a lot of nurse costumes that while excellent, get thrown off when you look at them and notice the color of the head/face is so very different than the body color. There's also a great shot of how the nurse face is constructed 25 seconds into the video.