Have a look at the reviews, I think some of the hired tens machines might be more popular. I just went for convenience and bought mine online.
I thought the same in terms of having options. Baby is back to back which means I could have a long and more painful labour. I'm thinking I want everything I possibly can use to get me through. Films, gym ball, baths, tens, hypnobirthing technique, chill out album playing etc..
DH was supposed to learn some of the key messages from the hypnobirthing cd to repeat to me.
He hasn't quite mastered them and 'breathe in the golden light' has become 'feel the sunshine coming through your fanny'. I figure that his positive reinforcement will keep me amused if nothing more.