Just a thought, have you checked with your Humane Society, see if they have any adoptable ones? They won't feed you a load of BS, they'll tell you to the best of their knowledge what the horse is like, health, temperment, etc.
I bought my first horse from an auction and they told me he was broke, the first time I rode him he took the bit from me and started bucking. You can't rely on the owners word, they just want rid of the horse. I kept him though and he is now 22 years old and I still ride him. If you are going to travel that far though you will need to be sure the horse will load and unload well because you need to stop periodically and at least walk the horse because more than a couple hour ride will make the muscles tense. Good luck and thank you for caring enough to ask for help.