What makes you the right person - any notable competition results, and the results of horses you've backed trained
facilities available
general rates and usual techniques used
plenty of contact details
I would spend an afternoon down there - watch them with the horses they currently have there... how they ride them do them handle them etc and see if you think they are up to scratch at looking after/breaking/handling your horse!
And references is a major thing i would want someone who has beenthere before to tell me they are up to the job!