I completely recommend HypnoBirthing! Can't comment on CalmBirth, because that's not what I did, but HB was very, very worth it. Probably the best money I've spent in relation to birth preparation, even more so than the IM's who we hired for our subsequent homebirth.
From all anecdotal evidence I've ever come across, no-one has a nice thing to say about labour induced artifically, so I'd like to direct you to Dr Sarah Buckley's work before you do anything else, to read about the effect on the hormone transfer during labour and birth, and even post-birth, of medical interventions. It will explain a lot about what you experienced and ought to dispel a few of your fears about going natural this time
Congrats and enjoy!