It’s strange that the cheapest is the Mornthong, because in Thailand it’s the most prized and most expensive kind! It’s got small seeds and a lot of very soft and tasty flesh but it’s the most selected. You can try it but I would prefer the Gradoom, which is a much wilder variety with a stronger, more typical taste. I don’t know about the other varieties they sell, except the Chanee, which is very common and cheap in Thailand but not at all the best, at least for me.
Overall, I find there’s often more difference between two durians of the same variety than between two durians of different varieties, the oldest trees giving the best ones. The ripest ones are also the best for me and I always specify “very ripe” when placing an order to Orkos. A ripe durian should open by itself, but in Thailand they open them with a machete, most of the time before they’re fully ripe. Of course, they should also be ripen on the tree as long as possible. Anyway, the Thai ones have a fairly constant decent quality, unlike in Indonesia and especially in Sri Lanka where they’re all different, smaller, much more wild and ranging from very bad inedible ones (harvested much too early or from bad trees, or even both!) to the most delicious ones, with the broadest range of unique flavors. A very good Sri Lanka durian would be much better than the best Thai one, but finding the most delectable one to you and suiting you best is a real pastime in Sri Lanka!
As durian are very rich in some specific nutrients (fats and proteins, I think), it’s normal that it repeals people being in overload of the same kind of nutrients such as Westerners having consumed lots of dairy products and/or being in constant nutritional overload.
I would ask the guys of this company: is it still possible to import non-irradiated fruit in US?