There's an importer in Florida, though I don't remember their name...
Also, Kachina Cadillac/Hummer in Scottsdale, AZ will import them as well - though they charge over $250 per tire for them~! this is for a tire that sells under a hundred bucks (US) for most sizes, in sri lanka according to a friend there.
Kachina tries to upsell the Jungle Trekker to hummer and escalade owners because they look cool which seems about all that hummer and cadillac truck owners care about. I found out that they import 'em because I was driving around and saw a hummer with Ouback Steakhouse logos painted on it and Simex tires. I emailed the regional manager of Outback restaurants and she got back to me directly the same day with where they were purchased and who to talk to (GREAT customer service on the part of Outback!) ... so I got in touch with Kachina and that was the scoop. $toomuch for me.
Reportedly, the extreme trekker (centipede) is virtually identical to the Interco swamper LTB in function. They look pretty similar, too - not tread pattern per se, but the depth of tread and % void look comparable.