I would stay away from the two year old as a barrel racing prospect for two reasons: 1) you really are supposed to wait until they are at least 5 years old and their bones are fused before barrel racing with them, which means you've got another three years to go, and 2) she's just two and already well started. That's pretty young to be starting a horse, and considering the intense career it will have as a barrel racer, that horse is all but bound to have soundness issues not too far down the road. Just my opinion, I'd rather an 8-9 year old seasoned barrel horse that knows what it's doing and is vet checked sound.
I've spent most of my life riding horses. The rest I've just wasted.