Take it from this guy who debunks basically everything about strains, there's no such thing. Vendors market it that way like cannabis but none of it really makes sense. Kratom is either good or it's not good. Whites CAN be slightly stimulating because they add the "bones" or the vein of the plant into the powder which is a mild stimulant, but otherwise you can get just as sedated if you take a high dose. I just go for anything green, whatever they call it, and haven't had issues for years. I stopped buying whites and reds because they were too inconsistent, reds often completely brown because they were sun dried and their alkaloids were destroyed, and whites just not being sedating enough for me. For any new user it will hardly matter what you use even if it's pretty bunk. But virtually every red "strain" I've bought has been completely brown, practically tasteless.
This site also debunks a lot about strains as well, particularly the names. So a strain like hulus kapua will most of the time not be from that area. Maeng Da is just a general term that translates to "pimp grade" basically. In other words, good stuff.
The guy on reddit personally went to Indonesia himself and found out a lot more. So all in all, you just want a potent batch, then you'll feel euphoric. Don't bother with names of strains and whatnot, placebo is pretty strong. It's a long but worthwhile read. This isn't to put down anyone else's experiences, but if you think a specific strain will do X or Y then that's incorrect. You either get good stuff or bad stuff. Kratom, to me, isn't necessarily a recreational drug. At first you can get pretty high and euphoric and for me the euphoria and body warmth never really went away, but I had to be strict about my doses. Tolerance to this stuff goes up extremely fast so you have to be consistent with how much you take.
Some people find MJ and kratom to be very euphoric, but MJ has always mostly overpowered it for me.