Anytime you begin a search for a new horse, it is a process. And when you are thinking of buying one that is some distance from you, there are many important factors to take into considerations.
First of all, know what you are looking for. This solves so many problems. There are so many horses out there, and so many breeds and within breeds so many bloodlines that influence and define the horse.
So know what you what your horse for and what you like. OK, ok enough right?
I have purchased alot of horses and many from great distances, and if I may.. here are some suggestions...
Do you have a good contact near or with the horse?
Photos and VIDEO are a must, to show clearly, conformation and movement, AND how does the horse work with people how are they in-hand?
Can you go and see the horse yourself? Or someone you know and knows you (like a riding buddy or a trainer) Because if this is your personal horse, personality is gong to be important.
Good Luck. And remember there are lots of horses out there be patience.