Wishing you the BEST in your pregnancy and birth journey.
My 3rd and 4th babies were waterbirths. I am also a CNM and at least 50% of my clients use water for labor and birth. Those of us who have "done it" both ways say how amazed we were that we could have a land birth, as the water experience was so much "easier".
I was so impressed with and LOVED my waterbirth experiences that I did my thesis in my MSN program on water for labor and birth.
As for Hypnobabies and Hynobirth, clients of mine who have used those methods were pleased, particularly with the relaxation during their pregnancies. It seemed the practice allowed them time to focus on their babies and themselves, and was much needed in their busy lives. Not one client has complained of not remembering or losing any of the labor process. I have a dear friend who teaches HypnoBabies classes (as well as being a massage therapist and a birth doula).
For answers to particular questions regarding birthing in water, I suggest you discuss yoru thoughts with your provider. As for the Hypno- birthing option, searching the 'net might offer answers which you want.
Again, Best Wishes!
L. (in Indianapolis)