Vida's got it nailed. Start bareback if you can. English is great to find your balance, but I figure if you're going to be falling off, better to be without the stirrups lol. However, if you're wanting to feel more secure, western is the way to go. I think starting bareback will teach you to trust your horse & yourself better and not put so much faith into the saddle. The styles aren't any easier or harder on the horse - I think it depends on the rider, but from what I remember, it's like 6 of one, half dozen of the other. On one hand, the western saddle is heavier - so could be misconstrued as harder on the horse, weight wise (english saddles are much lighter usually).... on the other hand, riding english, you're supposed to keep contact on the bit (big no no in western - loose reins are the norm) - which could be taken for harder on the horse's mouth. I say - try both, and see what YOU like better. Then you'll know what is best for YOU to start with.
Ask Often, Demand Nothing, and Reward Generously.