Career decision help?

I currently work in a bank and have applied for a job in the same company for the next position up, I'm really good at my job, it involves sales as well as customer service and I hit my targets every month. The only thing is, I'm just not that interested in the job itself, I do find it quite boring and to tell the truth I am sick to death of sitting on my backside all day. I have however, seen a job advertised working with race horses, I absolutely love horses and have been around them all my life, I am a strong rider and have enough experience for the job. I'm just not sure though of the career progression in this field, would someone be able to tell me what options there are for progression in this field, and also whether I would be making the right decision leaving my bank job? I really don't know which is the right decision and I don't know whether my heart is ruling my head.