I would tell you that given your location, if you really want this purchase to be clean, you might want to look at using an agent or company here in the US. If you sign an agreement with them and the car you receive turns out not to be good, you will have legal rights in the US (as in you can sue them), if you go it alone as you indicate, you will have no recourse once it arrives. Id love to tell you that people are honest and all that, but that isnt the case and what you think is unacceptable someone else may think is just fine.
One thing you didn't note was what kind of budget you are working with or is this a "price is not a concern" issue?
good luck with your search.