My brother lives in Costa Rica and drives a 100 series. They are available, but as expensive as they are here. I have investigated this for 2 years and have come up with no legal, relatively cheap way to bring one in. The guys that bring them in for armoring will not sell one without their work done and that becomes really expensive. Here are a couple of ways I have seen personally work:
1- find someone in the armed forces that will buy one where they are stationed and have them bring it home. They are allowed to do this, I think only once.
2- find someone living in a country that has the model you want and have them buy it and bring it with them when they come over here to visit. Then they could either wreck it, or take a chance and leave it here unwrecked. Wrecking it would be the thing. Not bad, maybe just show that they blew the motor and transmission. That way their government is satisfied and our government is satisfied. I am not sure how bad it would have to be. I am also not sure of their country's rules on bringing it back.
I say this because I have a friend that came over from Switzerland with his cool 6x6 motorhome and motorcycle on a 1 year vaction. He and the vehicles never left. He got his green card. He still drives the vehicles.
It will work, but registration issues are up to you.